user_id
stringlengths 24
24
| time
stringlengths 24
24
| feature_type
stringclasses 5
values | feature_version
stringclasses 2
values | input_question
stringlengths 1
1.24k
⌀ | input_code
stringlengths 2
18.5k
⌀ | input_intention
stringlengths 1
2.48k
⌀ | input_task_description
stringlengths 18
3.32k
⌀ |
|---|---|---|---|---|---|---|---|
63c6489e5f004bf4898cfe23 | 2023-01-27T07:00:07.547Z | General Question | v1 | What is the issue here:
==36527== Invalid write of size 4
==36527== at 0x1092C9: split_array (split_array.c:25)
==36527== by 0x1093BC: main (split_array.c:59)
==36527== Address 0x4a73144 is 4 bytes inside a block of size 6 alloc'd
==36527== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==36527== by 0x109245: split_array (split_array.c:19)
==36527== by 0x1093BC: main (split_array.c:59)
==36527== | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-27T20:39:59.150Z | Question from Code | v1 | What is this memory error allocation error that is caused from the code?
==40742== Invalid write of size 4
==40742== at 0x10929A: split_array (split_array.c:22)
==40742== by 0x1093B3: main (split_array.c:57)
==40742== Address 0x4a730e4 is 0 bytes after a block of size 4 alloc'd
==40742== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==40742== by 0x109224: split_array (split_array.c:17)
==40742== by 0x1093B3: main (split_array.c:57)
| #include <stdio.h>
#include <stdlib.h>
/* Return a pointer to an array of two dynamically allocated arrays of ints.
The first array contains the elements of the input array s that are
at even indices. The second array contains the elements of the input
array s that are at odd indices.
Do not allocate any more memory than necessary. You are not permitted
to include math.h. You can do the math with modulo arithmetic and integer
division.
*/
int **split_array(const int *s, int length) {
// the array containg the two pointers to the even and odd arrays
int **complete_arr = malloc(sizeof(int*) * 2);
// even array
complete_arr[0] = malloc(sizeof(int)*(length/2));
// odd array
complete_arr[1] = malloc(sizeof(int)*(length/2));
for (int i = 0; i < length; i++) {
if (i % 2 == 0) {
complete_arr[0][i/2] = s[i];
}
else {
complete_arr[1][i/2] = s[i];
}
}
return complete_arr;
}
/* Return a pointer to an array of ints with size elements.
- strs is an array of strings where each element is the string
representation of an integer.
- size is the size of the array
*/
int *build_array(char **strs, int size) {
// Create dynamic array
int *arr = malloc(sizeof(int)*size);
// Convert string to integers
for (int i = 0; i < size; i++){
// the first element is always the name of the program and argv is an array of strings
if (i != 0) {
arr[i - 1] = strtol(strs[i], NULL, 10); // Something is wrong here
}
}
return arr;
}
int main(int argc, char **argv) {
/* Replace the comments in the next two lines with the appropriate
arguments. Do not add any additional lines of code to the main
function or make other changes.
*/
int *full_array = build_array(argv, argc);
int **result = split_array(full_array, argc);
printf("Original array:\n");
for (int i = 0; i < argc - 1; i++) {
printf("%d ", full_array[i]);
}
printf("\n");
printf("result[0]:\n");
for (int i = 0; i < argc / 2; i++) {
printf("%d ", result[0][i]);
}
printf("\n");
printf("result[1]:\n");
for (int i = 0; i < (argc - 1) / 2; i++) {
printf("%d ", result[1][i]);
}
printf("\n");
free(full_array);
free(result[0]);
free(result[1]);
free(result);
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-01-27T20:42:45.245Z | General Question | v1 | What is this error?
==40742== Invalid write of size 4 ==40742== at 0x10929A: split_array (split_array.c:22) ==40742== by 0x1093B3: main (split_array.c:57) ==40742== Address 0x4a730e4 is 0 bytes after a block of size 4 alloc'd ==40742== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so) ==40742== by 0x109224: split_array (split_array.c:17) ==40742== by 0x1093B3: main (split_array.c:57)
| null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-27T20:58:08.989Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <stdlib.h>
/* Return a pointer to an array of two dynamically allocated arrays of ints.
The first array contains the elements of the input array s that are
at even indices. The second array contains the elements of the input
array s that are at odd indices.
Do not allocate any more memory than necessary. You are not permitted
to include math.h. You can do the math with modulo arithmetic and integer
division.
*/
int **split_array(const int *s, int length) {
// the array containg the two pointers to the even and odd arrays
int **complete_arr = malloc(sizeof(int*) * 2);
// even array
complete_arr[0] = malloc(sizeof(int)*(length/2));
// odd array
complete_arr[1] = malloc(sizeof(int)*(length/2));
for (int i = 0; i < length; i++) {
if (i % 2 == 0) {
complete_arr[0][i/2] = s[i];
}
else {
complete_arr[1][i/2] = s[i];
}
}
return complete_arr;
}
/* Return a pointer to an array of ints with size elements.
- strs is an array of strings where each element is the string
representation of an integer.
- size is the size of the array
*/
int *build_array(char **strs, int size) {
// Create dynamic array
int *arr = malloc(sizeof(int)*size);
// Convert string to integers
for (int i = 0; i < size; i++){
// the first element is always the name of the program and argv is an array of strings
if (i != 0) {
arr[i - 1] = strtol(strs[i], NULL, 10); // Something is wrong here
}
}
return arr;
}
int main(int argc, char **argv) {
/* Replace the comments in the next two lines with the appropriate
arguments. Do not add any additional lines of code to the main
function or make other changes.
*/
int *full_array = build_array(argv, argc);
int **result = split_array(full_array, argc);
printf("Original array:\n");
for (int i = 0; i < argc - 1; i++) {
printf("%d ", full_array[i]);
}
printf("\n");
printf("result[0]:\n");
for (int i = 0; i < argc / 2; i++) {
printf("%d ", result[0][i]);
}
printf("\n");
printf("result[1]:\n");
for (int i = 0; i < (argc - 1) / 2; i++) {
printf("%d ", result[1][i]);
}
printf("\n");
free(full_array);
free(result[0]);
free(result[1]);
free(result);
return 0;
} | It should not cause any memory issues | null |
63c6489e5f004bf4898cfe23 | 2023-01-27T20:59:35.547Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <stdlib.h>
/* Return a pointer to an array of two dynamically allocated arrays of ints.
The first array contains the elements of the input array s that are
at even indices. The second array contains the elements of the input
array s that are at odd indices.
Do not allocate any more memory than necessary. You are not permitted
to include math.h. You can do the math with modulo arithmetic and integer
division.
*/
int **split_array(const int *s, int length) {
// the array containg the two pointers to the even and odd arrays
int **complete_arr = malloc(sizeof(int*) * 2);
// even array
complete_arr[0] = malloc(sizeof(int)*(length/2));
// odd array
complete_arr[1] = malloc(sizeof(int)*(length/2));
for (int i = 0; i < length; i++) {
if (i % 2 == 0) {
complete_arr[0][i/2] = s[i];
}
else {
complete_arr[1][i/2] = s[i];
}
}
return complete_arr;
}
/* Return a pointer to an array of ints with size elements.
- strs is an array of strings where each element is the string
representation of an integer.
- size is the size of the array
*/
int *build_array(char **strs, int size) {
// Create dynamic array
int *arr = malloc(sizeof(int)*size);
// Convert string to integers
for (int i = 0; i < size; i++){
// the first element is always the name of the program and argv is an array of strings
if (i != 0) {
arr[i - 1] = strtol(strs[i], NULL, 10); // Something is wrong here
}
}
return arr;
}
int main(int argc, char **argv) {
/* Replace the comments in the next two lines with the appropriate
arguments. Do not add any additional lines of code to the main
function or make other changes.
*/
int *full_array = build_array(argv, argc);
int **result = split_array(full_array, argc);
printf("Original array:\n");
for (int i = 0; i < argc - 1; i++) {
printf("%d ", full_array[i]);
}
printf("\n");
printf("result[0]:\n");
for (int i = 0; i < argc / 2; i++) {
printf("%d ", result[0][i]);
}
printf("\n");
printf("result[1]:\n");
for (int i = 0; i < (argc - 1) / 2; i++) {
printf("%d ", result[1][i]);
}
printf("\n");
free(full_array);
free(result[0]);
free(result[1]);
free(result);
return 0;
} | How to not allocate any more memory than needed. | null |
63c6489e5f004bf4898cfe23 | 2023-01-28T21:21:03.459Z | General Question | v1 | How to find the number of files on ls -l in C? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-28T21:22:16.361Z | General Question | v1 | How to find the number of files on ls -l in C using scanf? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-28T21:24:17.613Z | General Question | v1 | How do you use scanf? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-28T21:25:33.611Z | General Question | v1 | How do you use scanf on the following?
total 329
-rwx------ 1 reid staff 1734 Jun 22 14:52 prog
-rw------- 1 reid staff 21510 Apr 6 12:10 tmp.txt
-rwxr-xr-x 1 reid staff 8968 Feb 1 2013 xyz
-rw-r--r-- 1 reid staff 88 Feb 15 2013 xyz.c
| null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-28T21:26:43.244Z | General Question | v1 | How do you skip the first line of ls-l?
total 329
-rwx------ 1 reid staff 1734 Jun 22 14:52 prog
-rw------- 1 reid staff 21510 Apr 6 12:10 tmp.txt
-rwxr-xr-x 1 reid staff 8968 Feb 1 2013 xyz
-rw-r--r-- 1 reid staff 88 Feb 15 2013 xyz.c | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-28T21:29:51.058Z | General Question | v1 | How do you read input into an array? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-01-28T23:45:11.058Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <stdlib.h>
// TODO: Implement a helper named check_permissions that matches the prototype below.
// int check_permissions(char *, char *);
int check_permissions(char *have, char *need) {
int missing = 0;
for (int i = 0; i < 11; i++) {
// Might have it changes to 9 idk yet lol
// Checks for char literal, '-' and if the position on the two arrays don't match
if (i != 0 && (need[i] != '-' && need[i] != have[i])){
missing += 1;
}
}
if (missing == 0){
return 0;
}
else {
return 1;
}
}
int main(int argc, char** argv) {
if (!(argc == 2 || argc == 3)) {
fprintf(stderr, "USAGE: count_large size [permissions]\n");
return 1;
}
// TODO: Process command line arguments.
// Read input of ls -l into variables for each column
char *perms = malloc(sizeof(char) * 10);
int fileSize = 0;
// The first line (Total: ...)
scanf("%*s %*d");
// TODO: Call check_permissions as part of your solution to count the files to
// compute and print the correct value.
int count = 0;
while (scanf("%s %*d %*s %*s %d %*s %*d %*s %*s", perms, &fileSize)!=EOF){
if (fileSize > argc && check_permissions(perms, *argv) == 0) {
count += 1;
}
}
// free variables and printf number of files
printf("%d\n", count);
free(perms);
return 0;
} | It should not always return 1 | null |
63c6489e5f004bf4898cfe23 | 2023-01-30T03:09:47.880Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <stdlib.h>
int main() {
int sin_array[9] = {1,2,3,4,5,6,7,8,9};
int sum = 0;
// Multiplying every 2nd digit by 2
for (int i = 0; i < 9; i++) {
// For odd i
if (i % 2 != 0) {
if (sin_array[i] * 2 >= 10) {
int temp = sin_array[i] * 2;
int sum_of_digits = 0;
while (temp > 0) {
int remainder = temp % 10;
temp = temp / 10;
sum_of_digits += remainder;
}
sin_array[i] = sum_of_digits;
}
else {
sin_array[i] *= 2;
}
}
}
// Add all sin_array digits together
int sum = 0;
for (int i = 0; i < 9; i++) {
sum += sin_array[i];
}
// Check if SIN is valid
if (sum % 10 == 0) {
printf("%s\n", "Valid Sin");
return 0; // It is valid
}
else {
printf("%s\n", "Invalid");
return 1;
}
} | It should compile and not return a segmentation fault error | null |
63c6489e5f004bf4898cfe23 | 2023-01-30T03:19:48.450Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <stdlib.h>
int main() {
int sin_array[9] = {1,2,3,4,5,6,7,8,9};
// Multiplying every 2nd digit by 2
for (int i = 0; i < 9; i++) {
// For odd i
if (i % 2 != 0) {
if (sin_array[i] * 2 >= 10) {
int temp = sin_array[i] * 2;
int sum_of_digits;
while (temp > 0) {
int remainder = temp % 10;
temp = temp / 10;
sum_of_digits += remainder;
}
sin_array[i] = sum_of_digits;
}
else {
sin_array[i] *= 2;
}
}
}
// Add all sin_array digits together
int sum;
for (int i = 0; i < 9; i++) {
sum += sin_array[i];
}
// Check if SIN is valid
if (sum % 10 == 0) {
printf("%s\n", "Valid Sin");
return 0; // It is valid
}
else {
printf("%s\n", "Invalid");
return 1;
}
} | How to get rid of runtime error? | null |
63c6489e5f004bf4898cfe23 | 2023-01-30T03:20:58.600Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <stdlib.h>
int main() {
int sin_array[9] = {1,2,3,4,5,6,7,8,9};
// Multiplying every 2nd digit by 2
for (int i = 0; i < 9; i++) {
// For odd i
if (i % 2 != 0) {
if (sin_array[i] * 2 >= 10) {
int temp = sin_array[i] * 2;
int sum_of_digits = 0;
while (temp > 0) {
int remainder = temp % 10;
temp = temp / 10;
sum_of_digits += remainder;
}
sin_array[i] = sum_of_digits;
}
else {
sin_array[i] *= 2;
}
}
}
// Add all sin_array digits together
int sum = 0;
for (int i = 0; i < 9; i++) {
sum += sin_array[i];
}
// Check if SIN is valid
if (sum % 10 == 0) {
printf("%s\n", "Valid Sin");
return 0; // It is valid
}
else {
printf("%s\n", "Invalid");
return 1;
}
} | Does not have a runtime error | null |
63c6489e5f004bf4898cfe23 | 2023-01-30T16:43:51.278Z | Explain Code | v1 | null | int main(int argc, char** argv) {
// If the number of argument is not equal to 2 or 3
if (!(argc == 2 || argc == 3)) {
fprintf(stderr, "USAGE: count_large size [permissions]\n");
return 1;
}
} | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-02T17:32:14.835Z | Help Fix Code | v1 | null | #include <stdlib.h>
#include <stdio.h>
#include <string.h>
/*
Write a function named truncate() that takes a string s and a
non-negative integer n. If s has more than n characters (not including the
null terminator), the function should truncate s at n characters and
return the number of characters that were removed. If s has n or
fewer characters, s is unchanged and the function returns 0. For example,
if s is the string "function" and n is 3, then truncate() changes s to
the string "fun" and returns 5.
*/
int truncate(char *s, int n) {
int numRemoved = 0;
if (strlen(s) > n) {
for (int i = strlen(s) - 1; i > n; i--){
// replace characters at n characters with '\0'
numRemoved += 1;
s[i] = '\0';
}
return numRemoved;
}
else {
return 0;
}
}
int main(int argc, char **argv) {
/* Do not change the main function */
if (argc != 3) {
fprintf(stderr, "Usage: truncate number string\n");
return 1;
}
int amt = strtol(argv[1], NULL, 10);
char *target = argv[2];
int soln_val = truncate(target, amt);
printf("%d %s\n", soln_val, target);
return 0;
}
| What is the segmentation fault in this code? | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:30:23.979Z | Help Write Code | v1 | null | null | null | /*
* Read in the location of the pixel array, the image width, and the image
* height in the given bitmap file.
*/ |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:39:16.151Z | Help Write Code | v1 | null | null | null | /* * Read in the location of the pixel array, the image width, and the image * height in the given bitmap file. */ |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:39:45.675Z | Help Write Code | v1 | null | null | null | /* * Read in the location of the pixel array, the image width, and the image * height in the given bitmap file. */ |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:40:03.555Z | Help Write Code | v1 | null | null | null | /* * Read in the location of the pixel array, the image width, and the image * height in the given bitmap file. */ |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:43:04.316Z | Help Write Code | v1 | null | null | null | Read in the location of the pixel array, the image width, and the image * height in the given bitmap file. |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:45:08.869Z | Help Write Code | v1 | null | null | null | /*
* Read in pixel array by following these instructions:
*
* 1. First, allocate space for m `struct pixel *` values, where m is the
* height of the image. Each pointer will eventually point to one row of
* pixel data.
* 2. For each pointer you just allocated, initialize it to point to
* heap-allocated space for an entire row of pixel data.
* 3. Use the given file and pixel_array_offset to initialize the actual
* struct pixel values. Assume that `sizeof(struct pixel) == 3`, which is
* consistent with the bitmap file format.
* NOTE: We've tested this assumption on the Teaching Lab machines, but
* if you're trying to work on your own computer, we strongly recommend
* checking this assumption!
* 4. Return the address of the first `struct pixel *` you initialized.
*/ |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:47:05.932Z | General Question | v1 | how can I use `struct pixel *` ? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:47:43.792Z | Question from Code | v1 | What is this code supposed to do? | /*
* Read in pixel array by following these instructions:
*
* 1. First, allocate space for m `struct pixel *` values, where m is the
* height of the image. Each pointer will eventually point to one row of
* pixel data.
* 2. For each pointer you just allocated, initialize it to point to
* heap-allocated space for an entire row of pixel data.
* 3. Use the given file and pixel_array_offset to initialize the actual
* struct pixel values. Assume that `sizeof(struct pixel) == 3`, which is
* consistent with the bitmap file format.
* NOTE: We've tested this assumption on the Teaching Lab machines, but
* if you're trying to work on your own computer, we strongly recommend
* checking this assumption!
* 4. Return the address of the first `struct pixel *` you initialized.
*/
struct pixel **read_pixel_array(FILE *image, int pixel_array_offset, int width, int height) {
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T19:51:50.060Z | Help Write Code | v1 | null | null | null | /*
* Read in pixel array by following these instructions:
*
* 1. First, allocate space for m `struct pixel *` values, where m is the
* height of the image. Each pointer will eventually point to one row of
* pixel data.
* 2. For each pointer you just allocated, initialize it to point to
* heap-allocated space for an entire row of pixel data.
* 3. Use the given file and pixel_array_offset to initialize the actual
* struct pixel values. Assume that `sizeof(struct pixel) == 3`, which is
* consistent with the bitmap file format.
* 4. Return the address of the first `struct pixel *` you initialized.
*/
struct pixel **read_pixel_array(FILE *image, int pixel_array_offset, int width, int height) {
}
|
63c6489e5f004bf4898cfe23 | 2023-02-10T20:08:32.011Z | General Question | v1 | What is returned when you loop through a bitmap image? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T20:13:29.929Z | Help Write Code | v1 | null | null | null | /* * Read in pixel array by following these instructions: * * 1. First, allocate space for m `struct pixel *` values, where m is the * height of the image. Each pointer will eventually point to one row of * pixel data. * 2. For each pointer you just allocated, initialize it to point to * heap-allocated space for an entire row of pixel data. * 3. Use the given file and pixel_array_offset to initialize the actual * struct pixel values. Assume that `sizeof(struct pixel) == 3`, which is * consistent with the bitmap file format. * 4. Return the address of the first `struct pixel *` you initialized. */ struct pixel **read_pixel_array(FILE *image, int pixel_array_offset, int width, int height) { } |
63c6489e5f004bf4898cfe23 | 2023-02-10T20:27:04.202Z | Question from Code | v1 | How to deallocate memory for the code? |
int main(int argc, char **argv) {
if (argc != 2) {
fprintf(stderr, "Usage: bitmap_printer input_bmp\n");
exit(1);
}
FILE *image = fopen(argv[1], "rb");
if (image == NULL) {
fprintf(stderr, "Cannot open file\n");
exit(1);
}
// Read in bitmap file metadata
int pixel_array_offset, width, height;
read_bitmap_metadata(image, &pixel_array_offset, &width, &height);
// Print out metadata.
printf("Pixel array offset: %d\n", pixel_array_offset);
printf("Width: %d\n", width);
printf("Height: %d\n", height);
// Read in the pixel data
struct pixel **pixels = read_pixel_array(image, pixel_array_offset, width, height);
// Print out some pixels from each of the image's corners.
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
print_pixel(pixels[i][j]);
print_pixel(pixels[i][width - 1 - j]);
print_pixel(pixels[height - 1 - i][j]);
print_pixel(pixels[height - 1 - i][width - 1 - j]);
}
}
// Clean up: you need to do this!
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T20:28:26.404Z | Question from Code | v1 | How do you free the memory for each row of pixels, and then free the memory for the array of rows? |
int main(int argc, char **argv) {
if (argc != 2) {
fprintf(stderr, "Usage: bitmap_printer input_bmp\n");
exit(1);
}
FILE *image = fopen(argv[1], "rb");
if (image == NULL) {
fprintf(stderr, "Cannot open file\n");
exit(1);
}
// Read in bitmap file metadata
int pixel_array_offset, width, height;
read_bitmap_metadata(image, &pixel_array_offset, &width, &height);
// Print out metadata.
printf("Pixel array offset: %d\n", pixel_array_offset);
printf("Width: %d\n", width);
printf("Height: %d\n", height);
// Read in the pixel data
struct pixel **pixels = read_pixel_array(image, pixel_array_offset, width, height);
// Print out some pixels from each of the image's corners.
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
print_pixel(pixels[i][j]);
print_pixel(pixels[i][width - 1 - j]);
print_pixel(pixels[height - 1 - i][j]);
print_pixel(pixels[height - 1 - i][width - 1 - j]);
}
}
// Clean up: you need to do this!
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T20:29:03.088Z | Question from Code | v1 | What is consider rows for pixels? |
int main(int argc, char **argv) {
if (argc != 2) {
fprintf(stderr, "Usage: bitmap_printer input_bmp\n");
exit(1);
}
FILE *image = fopen(argv[1], "rb");
if (image == NULL) {
fprintf(stderr, "Cannot open file\n");
exit(1);
}
// Read in bitmap file metadata
int pixel_array_offset, width, height;
read_bitmap_metadata(image, &pixel_array_offset, &width, &height);
// Print out metadata.
printf("Pixel array offset: %d\n", pixel_array_offset);
printf("Width: %d\n", width);
printf("Height: %d\n", height);
// Read in the pixel data
struct pixel **pixels = read_pixel_array(image, pixel_array_offset, width, height);
// Print out some pixels from each of the image's corners.
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
print_pixel(pixels[i][j]);
print_pixel(pixels[i][width - 1 - j]);
print_pixel(pixels[height - 1 - i][j]);
print_pixel(pixels[height - 1 - i][width - 1 - j]);
}
}
// Clean up: you need to do this!
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T20:29:40.586Z | Question from Code | v1 | is the rows of pixels called height or width in this code? |
int main(int argc, char **argv) {
if (argc != 2) {
fprintf(stderr, "Usage: bitmap_printer input_bmp\n");
exit(1);
}
FILE *image = fopen(argv[1], "rb");
if (image == NULL) {
fprintf(stderr, "Cannot open file\n");
exit(1);
}
// Read in bitmap file metadata
int pixel_array_offset, width, height;
read_bitmap_metadata(image, &pixel_array_offset, &width, &height);
// Print out metadata.
printf("Pixel array offset: %d\n", pixel_array_offset);
printf("Width: %d\n", width);
printf("Height: %d\n", height);
// Read in the pixel data
struct pixel **pixels = read_pixel_array(image, pixel_array_offset, width, height);
// Print out some pixels from each of the image's corners.
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
print_pixel(pixels[i][j]);
print_pixel(pixels[i][width - 1 - j]);
print_pixel(pixels[height - 1 - i][j]);
print_pixel(pixels[height - 1 - i][width - 1 - j]);
}
}
// Clean up: you need to do this!
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-02-10T20:48:14.124Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <stdlib.h>
#include "bitmap.h"
/*
* Read in the location of the pixel array, the image width, and the image
* height in the given bitmap file.
*/
void read_bitmap_metadata(FILE *image, int *pixel_array_offset, int *width, int *height) {
// store the location of the start of the pixel array
fseek(image, 10, SEEK_SET);
fread(&pixel_array_offset, sizeof(int), 1, image);
// store location of image width
fseek(image, 18, SEEK_SET);
fread(&width, sizeof(int), 1, image);
// store location of image height
fseek(image, 22, SEEK_SET);
fread(&height, sizeof(int), 1, image);
//for (i = 0; i < 4; i++) {
// pixel_array_offset[i] = fread()
//}
}
/*
* Read in pixel array by following these instructions:
*
* 1. First, allocate space for m `struct pixel *` values, where m is the
* height of the image. Each pointer will eventually point to one row of
* pixel data.
* 2. For each pointer you just allocated, initialize it to point to
* heap-allocated space for an entire row of pixel data.
* 3. Use the given file and pixel_array_offset to initialize the actual
* struct pixel values. Assume that `sizeof(struct pixel) == 3`, which is
* consistent with the bitmap file format.
* NOTE: We've tested this assumption on the Teaching Lab machines, but
* if you're trying to work on your own computer, we strongly recommend
* checking this assumption!
* 4. Return the address of the first `struct pixel *` you initialized.
*/
struct pixel **read_pixel_array(FILE *image, int pixel_array_offset, int width, int height) {
// Step 1
struct pixel **pixel_data = malloc(sizeof(struct pixel *) * height);
// Step 2 (change to while loop later)
for (int i = 0; i < height; i++) {
pixel_data[i] = malloc(sizeof(struct pixel) * width);
}
// Step 3
fseek(image, pixel_array_offset, SEEK_SET);
for (int h = 0; h < height; h++) {
fread(pixel_data[h], sizeof(struct pixel), width, image);
}
return pixel_data;
}
/*
* Print the blue, green, and red colour values of a pixel.
* You don't need to change this function.
*/
void print_pixel(struct pixel p) {
printf("(%u, %u, %u)\n", p.blue, p.green, p.red);
}
| It should not give a segmentation fault | null |
63c6489e5f004bf4898cfe23 | 2023-02-12T15:20:22.468Z | Help Write Code | v1 | null | null | null | /*
* Create a new user with the given name. Insert it at the tail of the list
* of users whose head is pointed to by *user_ptr_add.
*
* Return:
* - 0 if successful
* - 1 if a user by this name already exists in this list
* - 2 if the given name cannot fit in the 'name' array
* (don't forget about the null terminator)
*/
int create_user(const char *name, User **user_ptr_add) {
// I think user are like nodes of linked list in this case?
return -1;
} |
63c6489e5f004bf4898cfe23 | 2023-02-12T15:23:09.008Z | General Question | v1 | How do you check if a name already exists in a linked list and traverse a linked list? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-13T20:45:20.325Z | Question from Code | v1 | How do you create a new User in main? | #include <time.h>
#define MAX_NAME 32 // Max username and profile_pic filename lengths
#define MAX_FRIENDS 10 // Max number of friends a user can have
typedef struct user {
char name[MAX_NAME];
char profile_pic[MAX_NAME]; // This is a *filename*, not the file contents.
struct post *first_post;
struct user *friends[MAX_FRIENDS];
struct user *next;
} User;
| null | null |
63c6489e5f004bf4898cfe23 | 2023-02-13T21:02:40.163Z | General Question | v1 | If you have a char array of size 5 and you you use strncpy to put a const char that has a length of 5, what happens? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-13T21:20:35.353Z | General Question | v1 | How do you use strncpy on a const char *? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-13T22:20:29.667Z | General Question | v1 | Is this allowed emily->next->user? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-13T23:06:09.628Z | Help Write Code | v1 | null | null | null | /*
* Change the filename for the profile pic of the given user.
*
* Return:
* - 0 on success.
* - 1 if the file does not exist or cannot be opened.
* - 2 if the filename is too long.
*/ |
63c6489e5f004bf4898cfe23 | 2023-02-13T23:07:17.614Z | Help Write Code | v1 | null | null | null | /*
* Change the filename for the profile pic of the given user.
*
* Return:
* - 0 on success.
* - 1 if the file does not exist or cannot be opened.
* - 2 if the filename is too long.
*/
int update_pic(User *user, const char *filename) {
return -1;
}
|
63c6489e5f004bf4898cfe23 | 2023-02-13T23:08:11.693Z | General Question | v1 | generate a detailed documentation of `fopen` with usage examples and explanations | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T18:22:37.907Z | Help Fix Code | v1 | null | /*
* Create a new user with the given name. Insert it at the tail of the list
* of users whose head is pointed to by *user_ptr_add.
*
* Return:
* - 0 if successful
* - 1 if a user by this name already exists in this list
* - 2 if the given name cannot fit in the 'name' array
* (don't forget about the null terminator)
*/
int create_user(const char *name, User **user_ptr_add) {
// Don't add a user if their name already exists in the list but still add
// user in if their name doesn't fit array and their name is unique.
// CASE ONE - if user_ptr_add is not NULL (there's one or more users), traverse through user linked list
User **curr = user_ptr_add;
if (user_ptr_add != NULL) {
while (curr->next != NULL){
if (name == curr->name){
return 1;
}
curr = curr->next;
}
}
// Turn name into a char array
int max_length = MAX_NAME - 1;
char *temp_username;
strcat(temp_username, name);
char *username;
strncpy(temp_username, username, max_length);
// CASE TWO
if (user_ptr_add == NULL || username != curr->name) {
// Create new user with name [Have to remember to deallocate memory later when program ends]
User *new_user = (User *)malloc(sizeof(User));
// Copy username into new_user
strncpy(username, new_user->name, max_length);
// sets the last user's next to point to new_user
curr->next = new_user;
// Check length of name
if (strlen(name) >= MAX_NAME) {
return 2;
}
else{
return 0;
}
}
else { // if the last user has the same name as the user we wanted to insert
return 1;
}
} | It should insert a user at the end of the linked list. | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T18:33:54.856Z | Help Fix Code | v1 | null | #include "friends.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
/*
* Create a new user with the given name. Insert it at the tail of the list
* of users whose head is pointed to by *user_ptr_add.
*
* Return:
* - 0 if successful
* - 1 if a user by this name already exists in this list
* - 2 if the given name cannot fit in the 'name' array
* (don't forget about the null terminator)
*/
int create_user(const char *name, User **user_ptr_add) {
// Don't add a user if their name already exists in the list but still add
// user in if their name doesn't fit array and their name is unique.
// Step 1: Traverse through user linked list
User **curr = user_ptr_add;
if (user_ptr_add != NULL) {
while (curr->next != NULL){
if (name == curr->name){
return 1;
}
curr = curr->next;
}
}
// Turn name into a char array
char *temp_username;
strcat(temp_username, name);
char *username;
strncpy(temp_username, username, MAX_NAME - 1);
// Step 1 - if user linked list is empty or Step 2: if we have completed traversing through linked list and curr -> name != username
if (user_ptr_add == NULL || username != curr->name) {
// Create new user with name [Have to remember to deallocate memory later when program ends]
User *new_user = (User *)malloc(sizeof(User));
// Copy username into new_user
strncpy(username, new_user->name, MAX_NAME - 1);
// Checks if it's an empty user list or not and insert user
if (user_ptr_add == NULL) {
user_ptr_add = new_user;
}
else {
// sets the last user's next to point to new_user
curr->next = new_user;
}
// Check length of name
if (strlen(name) >= MAX_NAME) {
return 2;
}
else{
return 0;
}
}
else { // if the last user has the same name as the user we wanted to insert
return 1;
}
} | It should insert a user at the end of the linked list.
| null |
63c6489e5f004bf4898cfe23 | 2023-02-14T18:41:17.269Z | Help Fix Code | v1 | null | #include "friends.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
/*
* Create a new user with the given name. Insert it at the tail of the list
* of users whose head is pointed to by *user_ptr_add.
*
* Return:
* - 0 if successful
* - 1 if a user by this name already exists in this list
* - 2 if the given name cannot fit in the 'name' array
* (don't forget about the null terminator)
*/
int create_user(const char *name, User **user_ptr_add) {
// Don't add a user if their name already exists in the list but still add
// user in if their name doesn't fit array and their name is unique.
// Step 1: Traverse through user linked list
User **curr = user_ptr_add;
if (user_ptr_add != NULL) {
while (*curr->next != NULL){
if (name == *curr->name){
return 1;
}
curr = *curr->next;
}
}
// Turn name into a char array
char *temp_username;
strcat(temp_username, name);
char *username;
strncpy(temp_username, username, MAX_NAME - 1);
// Step 1 - if user linked list is empty OR
// Step 2: if we have completed traversing through linked list and curr -> name != username
if (user_ptr_add == NULL || username != *curr->name) {
// Create new user with name
User *new_user = (User *)malloc(sizeof(User));
// Copy username into new_user
strncpy(username, new_user->name, MAX_NAME - 1);
// Checks if it's an empty user list or not and insert user
if (user_ptr_add == NULL) {
user_ptr_add = new_user;
}
else {
// sets the last user's next to point to new_user
*curr->next = new_user;
}
// Check length of name
if (strlen(name) >= MAX_NAME) {
return 2;
}
else{
return 0;
}
}
else { // if the last user has the same name as the user we wanted to insert
return 1;
}
}
| How to get rid of error "member reference base type 'User *' (aka 'struct user *') is not a structure or union" | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T18:44:46.655Z | General Question | v1 | How do you access member of a struct if given a pointer to a pointer to the struct? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T19:06:23.937Z | General Question | v1 | What is this error: friends.c:30:20: error: member reference base type 'User *' (aka 'struct user *') is not a structure or union
while (curr->next != NULL){? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T19:34:07.815Z | Help Fix Code | v1 | null | /*
* Create a new user with the given name. Insert it at the tail of the list
* of users whose head is pointed to by *user_ptr_add.
*
* Return:
* - 0 if successful
* - 1 if a user by this name already exists in this list
* - 2 if the given name cannot fit in the 'name' array
* (don't forget about the null terminator)
*/
int create_user(const char *name, User **user_ptr_add) {
// Don't add a user if their name already exists in the list but still add
// user in if their name doesn't fit array and their name is unique.
// Checks if user linked list is empty or not
if (user_ptr_add != NULL) {
User *curr = *user_ptr_add; // Dereference so it points to a pointer of User !!
// Step 1: Traverse through user linked list
while (curr->next != NULL){
if (name == curr->name){
return 1;
}
curr = curr->next;
}
// Checks if last user has the same name as user you want to add
if ((char *) name != curr->name) {
// Create new user with name
User *new_user = (User *)malloc(sizeof(User));
// Copy username into new_user
strncpy((char *) name, new_user->name, MAX_NAME - 1);
// sets the last user's next to point to new_user
curr->next = new_user;
}
else {
return 1;
}
}
else {
// Create new user with name
User *new_user = (User *)malloc(sizeof(User));
// Copy username into new_user
strncpy((char *) name, new_user->name, MAX_NAME - 1);
// sets new user to be the head of the linked list
user_ptr_add = &new_user;
}
// Check length of name
if (strlen(name) >= MAX_NAME) {
return 2;
}
else{
return 0;
}
}
| Does not have segmentation faults | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T20:23:04.432Z | Question from Code | v1 | How do you create new User using this struct? | /*
* Create a new user with the given name. Insert it at the tail of the list
* of users whose head is pointed to by *user_ptr_add.
*
* Return:
* - 0 if successful
* - 1 if a user by this name already exists in this list
* - 2 if the given name cannot fit in the 'name' array
* (don't forget about the null terminator)
*/
int create_user(const char *name, User **user_ptr_add) {
// Don't add a user if their name already exists in the list but still add
// user in if their name doesn't fit array and their name is unique.
// Checks if user linked list is empty or not
if (user_ptr_add != NULL) {
User *curr = *user_ptr_add; // Dereference so it points to a pointer of User !!
// Step 1: Traverse through user linked list
while (curr->next != NULL){
if (name == curr->name){
return 1;
}
curr = curr->next;
}
// Checks if last user has the same name as user you want to add
if ((char *) name != curr->name) {
// Create new user with name
User *new_user = (User *)malloc(sizeof(User));
// Copy username into new_user
strncpy((char *) name, new_user->name, MAX_NAME - 1);
// sets the last user's next to point to new_user
curr->next = new_user;
}
else {
return 1;
}
}
else {
// Create new user with name
User *new_user = (User *)malloc(sizeof(User));
// Copy username into new_user
strncpy((char *) name, new_user->name, MAX_NAME - 1);
// sets new user to be the head of the linked list
user_ptr_add = &new_user;
}
// Check length of name
if (strlen(name) >= MAX_NAME) {
return 2;
}
else{
return 0;
}
}
#include <time.h>
#define MAX_NAME 32 // Max username and profile_pic filename lengths
#define MAX_FRIENDS 10 // Max number of friends a user can have
typedef struct user {
char name[MAX_NAME];
char profile_pic[MAX_NAME]; // This is a *filename*, not the file contents.
struct post *first_post;
struct user *friends[MAX_FRIENDS];
struct user *next;
} User; | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T20:24:54.706Z | Question from Code | v1 | How to create new User struct? | #include <time.h>
#define MAX_NAME 32 // Max username and profile_pic filename lengths
#define MAX_FRIENDS 10 // Max number of friends a user can have
typedef struct user {
char name[MAX_NAME];
char profile_pic[MAX_NAME]; // This is a *filename*, not the file contents.
struct post *first_post;
struct user *friends[MAX_FRIENDS];
struct user *next;
} User; | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T21:36:43.238Z | General Question | v1 | How do you add to char array? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-14T23:07:44.470Z | Help Write Code | v1 | null | null | null | /*
* Change the filename for the profile pic of the given user.
*
* Return:
* - 0 on success.
* - 1 if the file does not exist or cannot be opened.
* - 2 if the filename is too long.
*/
int update_pic(User *user, const char *filename) {
return -1;
} |
63c6489e5f004bf4898cfe23 | 2023-02-14T23:09:39.430Z | Help Write Code | v1 | null | null | null | /*
* Change the filename for the profile pic of the given user.
*
* Return:
* - 0 on success.
* - 1 if the file does not exist or cannot be opened.
* - 2 if the filename is too long.
*/
int update_pic(User *user, const char *filename) {
return -1;
} |
63c6489e5f004bf4898cfe23 | 2023-02-14T23:10:03.601Z | Help Write Code | v1 | null | null | null | /*
* Change the filename for the profile pic of the given user.
*
* Return:
* - 0 on success.
* - 1 if the file does not exist or cannot be opened.
* - 2 if the filename is too long.
*/
int update_pic(User *user, const char *filename) |
63c6489e5f004bf4898cfe23 | 2023-02-15T02:07:05.682Z | Help Fix Code | v1 | null | /*
* Make two users friends with each other. This is symmetric - a pointer to
* each user must be stored in the 'friends' array of the other.
*
* New friends must be added in the first empty spot in the 'friends' array.
*
* Return:
* - 0 on success.
* - 1 if the two users are already friends.
* - 2 if the users are not already friends, but at least one already has
* MAX_FRIENDS friends.
* - 3 if the same user is passed in twice.
* - 4 if at least one user does not exist.
*
* Do not modify either user if the result is a failure.
* NOTE: If multiple errors apply, return the *largest* error code that applies.
*/
int make_friends(const char *name1, const char *name2, User *head) {
int largest_error = 0;
User *user_1 = find_user(name1, head);
User *user_2 = find_user(name2, head);
// If the same user is passed in twice
if (user_1 == user_2) {
if (largest_error < 3){
largest_error = 3;
}
}
// If at least one user doesn't exists
if (user_1 == NULL || user_2 == NULL) {
if (largest_error < 4){
largest_error = 4;
}
}
// Go through user_1's friend's list
User *curr = user_1->friends[0];
User *curr2 = user_2->friends[0];
int num_user1 = 0;
int num_user2 = 0;
int not_friends = 0;
while (curr->next != NULL) {
// Go through user_2's friend's list
while (curr2->next != NULL) {
// If the two users are already friends
if (curr2 == curr) {
not_friends += 1;
if (largest_error < 1) {
largest_error = 1;
}
}
curr2 = curr2->next;
num_user2 += 1;
}
curr = curr->next;
num_user1 += 1;
}
// If users are not already friends but one of them have max number of friends
if (not_friends != 0 && (num_user1 == MAX_FRIENDS || num_user2 == MAX_FRIENDS)) {
if (largest_error < 2) {
largest_error = 2;
}
}
// Success
else if (not_friends == 0 && (num_user1 < MAX_FRIENDS && num_user2 < MAX_FRIENDS)) {
curr->next = user_2;
curr2->next = user_1;
}
return largest_error;
} | Get rid of segmentation fault | null |
63c6489e5f004bf4898cfe23 | 2023-02-15T12:54:35.277Z | Help Fix Code | v1 | null | /*
* Print a user profile.
* For an example of the required output format, see the example output
* linked from the handout.
* Return:
* - 0 on success.
* - 1 if the user is NULL.
*/
int print_user(const User *user) {
if (user != NULL) {
// Open profile picture
FILE *file = fopen(user->profile_pic, "r");
char char_part;
while (file != NULL && (char_part = fgetc(file)) != EOF) {
printf("%c", char_part);
}
if (file != NULL) {
printf("\n");
}
fclose(file);
// Print out name
printf("%s %s\n", "Name:", user->name);
printf("%s\n", "------------------------------------------");
// Make friends section
printf("%s\n", "Friends:");
int i = 0;
while (i < MAX_FRIENDS && (user->friends[i] != NULL)) {
printf("\t%s\n", user->friends[i]->name);
i += 1;
}
printf("%s\n", "------------------------------------------");
// Make post section
printf("%s\n", "Posts:");
Post *curr = user->first_post;
while (curr != NULL){
printf("%s %s\n", "From:", curr->author);
printf("%s %s\n", "Date:", ctime(curr->date));
printf("\n");
printf("%s\n", curr->contents);
if (curr->next != NULL) { // Checks if there is another post
printf("\n");
printf("%s\n", "===");
printf("\n");
}
curr = curr->next;
}
printf("%s\n", "------------------------------------------");
return 0;
}
else {
// User is NULL
return 1;
}
} | How to get rid to segmentation fault? | null |
63c6489e5f004bf4898cfe23 | 2023-02-15T13:03:29.496Z | Help Fix Code | v1 | null | /*
* Print a user profile.
* For an example of the required output format, see the example output
* linked from the handout.
* Return:
* - 0 on success.
* - 1 if the user is NULL.
*/
int print_user(const User *user) {
if (user != NULL) {
// Open profile picture
FILE *file = fopen(user->profile_pic, "r");
char char_part;
while (file != NULL && (char_part = fgetc(file)) != EOF) {
printf("%c", char_part);
}
if (file != NULL) {
printf("\n");
}
fclose(file);
// Print out name
printf("%s %s\n", "Name:", user->name);
printf("%s\n", "------------------------------------------");
// Make friends section
printf("%s\n", "Friends:");
int i = 0;
while (i < MAX_FRIENDS) {
if (user->friends[i] != NULL) {
printf("%s\n", user->friends[i]->name);
}
i += 1;
}
printf("%s\n", "------------------------------------------");
// Make post section
printf("%s\n", "Posts:");
Post *curr = user->first_post;
while (curr != NULL){
printf("%s %s\n", "From:", curr->author);
printf("%s %s\n", "Date:", ctime(curr->date));
printf("\n");
printf("%s\n", curr->contents);
if (curr->next != NULL) { // Checks if there is another post
printf("\n");
printf("%s\n", "===");
printf("\n");
}
curr = curr->next;
}
printf("%s\n", "------------------------------------------");
return 0;
}
// User is NULL
return 1;
}
| No segmentation fault | null |
63c6489e5f004bf4898cfe23 | 2023-02-15T15:34:49.013Z | Help Fix Code | v1 | null | /*
* Make a new post from 'author' to the 'target' user,
* containing the given contents, IF the users are friends.
*
* Insert the new post at the *front* of the user's list of posts.
*
* 'contents' is a pointer to heap-allocated memory - you do not need
* to allocate more memory to store the contents of the post.
*
* Return:
* - 0 on success
* - 1 if users exist but are not friends
* - 2 if either User pointer is NULL
*/
int make_post(const User *author, User *target, char *contents) {
// Checks if either user pointer are NULL
if (author == NULL || target == NULL) {
return 2;
}
// Checks if users are friends
int i = 0;
int they_are_friends = 0;
while (i < MAX_FRIENDS) {
if ((author->friends[i] != NULL) && author->friends[i]->name == target->name) {
they_are_friends += 1;
}
if ((target->friends[i] != NULL) && target->friends[i]->name == author->name) {
they_are_friends += 1;
}
i += 1;
}
if (they_are_friends == 0) {
return 1;
}
else {
// SEG FAULT HERE!!!
// They are friends and add post content to target's profile
Post *a_post = (Post *)malloc(sizeof(Post));
strcpy(a_post->author, (char *) author);
strcpy(a_post->contents, contents); // IDK About this part
// Get time
time_t posted_datetime = time(NULL);
*a_post->date = posted_datetime;
// Insert new post
if (target->first_post != NULL) {
// NOT too sure about this part
a_post->next = target->first_post;
target->first_post = a_post->next;
}
else{
target->first_post = a_post;
a_post->next = NULL;
}
return 0;
}
} | How to make Post properly and get rid of segmentation fault? | null |
63c6489e5f004bf4898cfe23 | 2023-02-15T16:15:37.657Z | Help Write Code | v1 | null | null | null | /*
* From the list pointed to by *user_ptr_del, delete the user
* with the given name.
* Remove the deleted user from any lists of friends.
*
* Return:
* - 0 on success.
* - 1 if a user with this name does not exist.
*/
int delete_user(const char *name, User **user_ptr_del) |
63c6489e5f004bf4898cfe23 | 2023-02-15T17:10:42.816Z | Help Fix Code | v1 | null | /*
* Make a new post from 'author' to the 'target' user,
* containing the given contents, IF the users are friends.
*
* Insert the new post at the *front* of the user's list of posts.
*
* 'contents' is a pointer to heap-allocated memory - you do not need
* to allocate more memory to store the contents of the post.
*
* Return:
* - 0 on success
* - 1 if users exist but are not friends
* - 2 if either User pointer is NULL
*/
int make_post(const User *author, User *target, char *contents) {
// Checks if either user pointer are NULL
if (author == NULL || target == NULL) {
return 2;
}
// Checks if users are friends
int i = 0;
int they_are_friends = 0;
while (i < MAX_FRIENDS) {
if ((author->friends[i] != NULL) && author->friends[i]->name == target->name) {
they_are_friends += 1;
}
if ((target->friends[i] != NULL) && target->friends[i]->name == author->name) {
they_are_friends += 1;
}
i += 1;
}
if (they_are_friends == 0) {
return 1;
}
else {
// They are friends and add post content to target's profile
Post *a_post = (Post *)malloc(sizeof(Post));
if (a_post == NULL) {
exit(1);
}
strcpy(a_post->author, author->name);
a_post->contents = contents;
// Get time
time_t *posted_datetime = malloc(sizeof(time_t));
if (posted_datetime == NULL) {
exit(1);
}
a_post->date = posted_datetime;
// Insert new post
if (target->first_post != NULL) {
// NOT too sure about this part
a_post->next = target->first_post;
target->first_post = a_post;
}
else{ // If the user has no post initially
target->first_post = a_post;
a_post->next = NULL;
}
return 0;
}
}
/*
* From the list pointed to by *user_ptr_del, delete the user
* with the given name.
* Remove the deleted user from any lists of friends.
*
* Return:
* - 0 on success.
* - 1 if a user with this name does not exist.
*/
int delete_user(const char *name, User **user_ptr_del) {
User *wanted_user = find_user(name, *user_ptr_del);
// Checks if the user was found
if (wanted_user == NULL) {
return 1;
}
User *curr = *user_ptr_del;
User *wanted_user_2;
// Look for user to delete by traversing through user linked list
while (curr != NULL){
// If there are more than one user in the program. If there is only one, head == user with name and they would have no friends.
if (curr->next != NULL && (strcmp(name, curr->next->name) == 0)){
wanted_user_2 = curr->next;
// Remove user off of their friends list
int i = 0;
while (i < MAX_FRIENDS && (wanted_user_2->friends[i] != NULL)) {
// Pop user off each of their friend's friend list
int j = 0;
while (j < MAX_FRIENDS && (wanted_user_2->friends[i][j] != NULL)) {
// Checks if the friend you found in the person's friend list is them
// Means that the first friend is the to be removed user
if (wanted_user_2->friends[i][0]->name == wanted_user_2->name) {
wanted_user_2->friends[i][0] = wanted_user_2->friends[i][0]->next; // IS THIS LEGAL???
}
// Checks if the next friend is not NULL and that they match the user you want to remove
else if (wanted_user_2->friends[i][j]->next != NULL && (wanted_user_2->friends[i][0]->next->name == wanted_user_2->name)) {
wanted_user_2->friends[i][j]->next = wanted_user_2->friends[i][j]->next->next;
}
// Checks if the user is at the end of the list
else if (wanted_user_2->friends[i][j]->next->next == NULL && (wanted_user_2->friends[i][0]->next->name == wanted_user_2->name)) {
wanted_user_2->friends[i][j]->next = NULL;
}
j+=1;
}
i += 1;
}
break;
}
curr = curr->next;
}
// Change the pointers
// If user is the head (IDK if you write * in front)
if (*user_ptr_del->next == NULL) {
*user_ptr_del = *user_ptr_del->next;
}
else {
// Set previous user of the wanted user to the user after the wanted user.
curr->next = curr->next->next;
}
// Free the user's post
Post *curr_post = wanted_user->first_post;
while (curr_post != NULL) {
free(curr_post->author);
free(curr_post->contents);
free(curr_post->date);
curr_post = curr_post->next;
}
// Free the user
free(user);
return 0;
}
| Get rid of errors. | null |
63c6489e5f004bf4898cfe23 | 2023-02-15T17:30:43.096Z | Help Fix Code | v1 | null | /*
* From the list pointed to by *user_ptr_del, delete the user
* with the given name.
* Remove the deleted user from any lists of friends.
*
* Return:
* - 0 on success.
* - 1 if a user with this name does not exist.
*/
int delete_user(const char *name, User **user_ptr_del) {
User *wanted_user = find_user(name, *user_ptr_del);
// Checks if the user was found
if (wanted_user == NULL) {
return 1;
}
User *curr = *user_ptr_del;
User *wanted_user_2;
// Look for user to delete by traversing through user linked list
while (curr != NULL){
// If there are more than one user in the program. If there is only one, head == user with name and they would have no friends.
if (curr->next != NULL && (strcmp(name, curr->next->name) == 0)){
wanted_user_2 = curr->next;
// Remove user off of their friends list
int i = 0;
while (i < MAX_FRIENDS && (wanted_user_2->friends[i] != NULL)) {
// Pop user off each of their friend's friend list
int j = 0;
while (j < MAX_FRIENDS && (wanted_user_2->friends[i]->friends[j] != NULL)) {
// Checks if the friend you found in the person's friend list is them
// Means that the first friend is the to be removed user
if (wanted_user_2->friends[i]->friends[0]->name == wanted_user_2->name) {
wanted_user_2->friends[i]->friends[0] = wanted_user_2->friends[i]->friends[0]->next; // IS THIS LEGAL???
}
// Checks if the next friend is not NULL and that they match the user you want to remove
else if (wanted_user_2->friends[i]->friends[j]->next != NULL && (wanted_user_2->friends[i]->friends[0]->next->name == wanted_user_2->name)) {
wanted_user_2->friends[i]->friends[j]->next = wanted_user_2->friends[i]->friends[j]->next->next;
}
// Checks if the user is at the end of the list
else if (wanted_user_2->friends[i]->friends[j]->next->next == NULL && (wanted_user_2->friends[i]->friends[0]->next->name == wanted_user_2->name)) {
wanted_user_2->friends[i]->friends[j]->next = NULL;
}
j+=1;
}
i += 1;
}
break;
}
curr = curr->next;
}
// Change the pointers
// If user is the head (IDK if you write * in front)
User *head = *user_ptr_del;
if (head->next == NULL) {
user_ptr_del = &head->next;
}
else {
// Set previous user of the wanted user to the user after the wanted user.
curr->next = curr->next->next;
}
// Free the user's post
Post *curr_post = wanted_user->first_post;
while (curr_post != NULL) {
free(curr_post->author);
free(curr_post->contents);
free(curr_post->date);
curr_post = curr_post->next;
}
// Free the user
free(wanted_user);
return 0;
}
| How to get rid of segmentation fault? | null |
63c6489e5f004bf4898cfe23 | 2023-02-15T23:24:44.769Z | Help Fix Code | v1 | null | /*
* Make a new post from 'author' to the 'target' user,
* containing the given contents, IF the users are friends.
*
* Insert the new post at the *front* of the user's list of posts.
*
* 'contents' is a pointer to heap-allocated memory - you do not need
* to allocate more memory to store the contents of the post.
*
* Return:
* - 0 on success
* - 1 if users exist but are not friends
* - 2 if either User pointer is NULL
*/
int make_post(const User *author, User *target, char *contents) {
// Checks if either user pointer are NULL
if (author == NULL || target == NULL) {
return 2;
}
// Checks if users are friends
int i = 0;
int they_are_friends = 0;
while (i < MAX_FRIENDS) {
if ((author->friends[i] != NULL) && author->friends[i]->name == target->name) {
they_are_friends += 1;
}
if ((target->friends[i] != NULL) && target->friends[i]->name == author->name) {
they_are_friends += 1;
}
i += 1;
}
if (they_are_friends == 0) {
return 1;
}
else {
// They are friends and add post content to target's profile
Post *a_post = (Post *)malloc(sizeof(Post));
if (a_post == NULL) {
exit(1);
}
strcpy(a_post->author, author->name);
a_post->contents = contents;
// Get time
time_t *posted_datetime = malloc(sizeof(time_t));
if (posted_datetime == NULL) {
exit(1);
}
a_post->date = posted_datetime;
// Insert new post
if (target->first_post != NULL) {
// NOT too sure about this part
a_post->next = target->first_post;
target->first_post = a_post;
}
else{ // If the user has no post initially
target->first_post = a_post;
a_post->next = NULL;
}
return 0;
}
}
/*
* From the list pointed to by *user_ptr_del, delete the user
* with the given name.
* Remove the deleted user from any lists of friends.
*
* Return:
* - 0 on success.
* - 1 if a user with this name does not exist.
*/
int delete_user(const char *name, User **user_ptr_del) {
User *wanted_user = find_user(name, *user_ptr_del);
User *curr = *user_ptr_del;
// Checks if the user was found
if (curr == NULL || wanted_user == NULL) {
return 1;
}
// Traverse through friends list and remove user from all friends list
for (int i = 0; i < MAX_FRIENDS; i++) {
if (wanted_user->friends[i] != NULL) {
int prev = 0;
// Go through their friend's list and remove them off of it
for (int j = 0; j < MAX_FRIENDS; j++) {
if (wanted_user->friends[i]->friends[j] != wanted_user) {
wanted_user->friends[i]->friends[prev] = wanted_user->friends[i]->friends[j];
prev +=1;
}
}
}
}
// Switch pointers to remove user from user linked list
while (curr != NULL) {
// If wanted_user is the head
if (*user_ptr_del == wanted_user) {
*user_ptr_del = curr->next;
}
// Have user point to the user beyond wanted_user
else if ((curr->next != NULL) && curr->next == wanted_user){
curr->next = curr->next->next;
}
curr = curr->next;
}
// Free the user's post
Post *curr_post = wanted_user->first_post;
while (curr_post != NULL) {
Post *new_post = curr_post->next;
free(curr_post->contents);
free(curr_post->date);
free(curr_post);
// Go to next post
curr_post = new_post;
}
// Free the user
free(wanted_user);
return 0;
} | How to free all memory? | null |
63c6489e5f004bf4898cfe23 | 2023-02-15T23:35:12.281Z | Help Fix Code | v1 | null | /*
* From the list pointed to by *user_ptr_del, delete the user
* with the given name.
* Remove the deleted user from any lists of friends.
*
* Return:
* - 0 on success.
* - 1 if a user with this name does not exist.
*/
int delete_user(const char *name, User **user_ptr_del) {
User *wanted_user = find_user(name, *user_ptr_del);
User *curr = *user_ptr_del;
// Checks if the user was found
if (curr == NULL || wanted_user == NULL) {
return 1;
}
// Traverse through friends list and remove user from all friends list
for (int i = 0; i < MAX_FRIENDS; i++) {
if (wanted_user->friends[i] != NULL) {
int prev = 0;
// Go through their friend's list and remove them off of it
for (int j = 0; j < MAX_FRIENDS; j++) {
if (wanted_user->friends[i]->friends[j] != wanted_user) {
wanted_user->friends[i]->friends[prev] = wanted_user->friends[i]->friends[j];
prev +=1;
}
}
}
}
// Switch pointers to remove user from user linked list
while (curr != NULL) {
// If wanted_user is the head
if (*user_ptr_del == wanted_user) {
*user_ptr_del = curr->next;
}
// Have user point to the user beyond wanted_user
else if ((curr->next != NULL) && curr->next == wanted_user){
curr->next = curr->next->next;
}
curr = curr->next;
}
// Free the user's post
Post *curr_post = wanted_user->first_post;
while (curr_post != NULL) {
Post *new_post = curr_post->next;
free(curr_post->contents);
free(curr_post->date);
free(curr_post);
// Go to next post
curr_post = new_post;
}
// Free the user
free(wanted_user);
return 0;
} | How to free all memory?
| null |
63c6489e5f004bf4898cfe23 | 2023-02-17T19:08:29.224Z | Help Write Code | v1 | null | null | null | /* Write the copy function to perform exactly as strncpy does, with one
exception: your copy function will guarantee that dest is always
null-terminated. Capacity is expected to be the number of bytes of
memory allocated to dest.
You shoud read the man page to learn how strncpy works.
NOTE: You must write this function without using any string functions.
The only function that should depend on string.h is memset.
*/
char *copy(char *dest, const char *src, int capacity) {
return dest;
} |
63c6489e5f004bf4898cfe23 | 2023-02-24T21:54:41.423Z | General Question | v1 | generate documentation for fopen() | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-24T21:56:58.439Z | General Question | v1 | generate documentation for strncpy() | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-24T22:02:05.662Z | General Question | v1 | Can you use strlen on a char array? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-24T22:08:52.814Z | General Question | v1 | generate documentation for strncat | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-24T22:21:00.075Z | General Question | v1 | generate documentation for fread | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-24T22:22:23.680Z | General Question | v1 | generate documentation for fscanf | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-25T03:52:44.946Z | General Question | v1 | generate documentation for strol | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-25T03:56:15.982Z | General Question | v1 | what is SEEK_SET? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-25T05:02:24.057Z | General Question | v1 | generate fseek documentation | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-25T20:40:38.674Z | General Question | v1 | What is *(p+2) += 1? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-25T20:55:25.487Z | General Question | v1 | how do you use a while loop on a member of a struct? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-02-26T05:23:54.322Z | Explain Code | v1 | null | struct event {
char *month;
int day;
};
/* Set the month and day of an event struct given a string in the format
* "MonthName DayNumber"
*
* For example, if arg is "December 25", the event’s month should be set to "December",
* and its day should be set to 25.
*/
void set_struct(struct event *e, char *arg) {
char *tmp = strchr(arg, ’ ’);
e->date = strtol(tmp + 1, NULL, 10);
int size = strlen(arg) - strlen(tmp) + 1;
e->month = malloc(sizeof(char) * size);
strncpy(e->month, arg, size - 1);
e->month[size] = ’\0’;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-02-26T05:50:31.035Z | Help Fix Code | v1 | null | #include <stdio.h>
#include <string.h>
#include <stdlib.h>
char *intertwine(char *s1, char *s2){
int i = 0;
char *collection = malloc(strlen(s1) + strlen(s2) + 1);
while(i / 2 < strlen(s1) && i / 2 < strlen(s2)){
collection[i] = s1[i / 2];
collection[i+1] = s2[i / 2];
i += 2;
}
if(i/2 >= strlen(s1)){
for(int j = i/2; j <= strlen(s2); j++){
collection[i / 2 + j] = s2[j];
}
}
else if(i/2 >= strlen(s2)){
for(int j = i/2; j <= strlen(s1); j++){
collection[i / 2 + j] = s1[j];
}
}
else {
collection[i] = '\0';
}
return collection;
} | Fix linker problem | null |
63c6489e5f004bf4898cfe23 | 2023-03-03T20:05:16.990Z | General Question | v1 | What is ppid? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-03T20:12:42.239Z | Explain Code | v1 | null | (base) Emilys-MacBook-Pro:lab7 moon$ ./forkloop 1
ppid = 5962, pid = 7395, i = 0
ppid = 1, pid = 7396, i = 0 | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-10T18:01:56.869Z | Help Write Code | v2 | null | null | null | Your task is to complete checkpasswd.c, which reads a user id and password from stdin, creates a new process to run the validate program, sends it the user id and password, and prints a message to stdout reporting whether the validation is successful.
Your program should use the exit status of the validate program to determine which of the three following messages to print:
"Password verified" if the user id and password match.
"Invalid password" if the user id exists, but the password does not match.
"No such user" if the user id is not recognized |
63c6489e5f004bf4898cfe23 | 2023-03-10T18:29:52.006Z | General Question | v2 | What is a file descriptor? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-10T21:25:14.348Z | Help Fix Code | v2 | It should be about to reach printf statements | int main(void) {
char user_id[MAXLINE];
char password[MAXLINE];
/* The user will type in a user name on one line followed by a password
on the next.
DO NOT add any prompts. The only output of this program will be one
of the messages defined above.
Please read the comments in validate carefully
*/
if(fgets(user_id, MAXLINE, stdin) == NULL) {
perror("fgets");
exit(1);
}
if(fgets(password, MAXLINE, stdin) == NULL) {
perror("fgets");
exit(1);
}
// File descriptor
int fd[2];
// Make the pipe
if ((pipe(fd)) == -1){
perror("pipe");
exit(1);
}
// Fork - Create a child process and store its id pid.
int pid = fork();
int read_end = fd[0];
int write_end = fd[1];
if (pid == 0) { // Runs child process
// reset stdin so it reads from the pipe
if (dup2(read_end, STDIN_FILENO) == -1) {
perror("dup2");
exit(1);
}
// close the write end of the pipe
if ((close(write_end)) == -1) {
perror("close");
}
// execute the validate program
execl("./validate", "validate", user_id, password, NULL);
}
else if (pid > 1) { // Runs parent process
// reset stdout so it reads from the pipe
if (dup2(write_end, STDOUT_FILENO) == -1) {
perror("dup2");
exit(1);
}
// close the write end of the pipe
if ((close(read_end)) == -1) {
perror("close");
}
int status;
pid_t child_pid = wait(&status);
if (child_pid == -1) {
perror("wait");
exit(1);
}
// Match is found
if (WEXITSTATUS(status) == 0) {
printf("%s\n", SUCCESS);
}
// Invalid password
else if (WEXITSTATUS(status) == 2) {
printf("%s\n", INVALID);
}
// User doesn't exists
else {
printf("%s\n", NO_USER);
}
}
else {
perror("fork");
exit(1);
}
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-03-10T23:07:36.203Z | Explain Code | v2 | null |
char line[MAXLINE];
while (fgets(line, sizeof(line) - 1, fp)) {
line[strlen(line) - 1] = '\0';
if (strcmp(userid, line) == 0) {
fclose(fp);
exit(0);
} else if (strncmp(userid, line, user_length) == 0) {
fclose(fp);
exit(2);
}
} | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-10T23:49:31.246Z | Help Write Code | v2 | null | null | null | Your task is to complete checkpasswd.c, which reads a user id and password from stdin, creates a new process to run the validate program, sends it the user id and password, and prints a message to stdout reporting whether the validation is successful. |
63c6489e5f004bf4898cfe23 | 2023-03-12T19:33:58.984Z | General Question | v2 | When should you use fscanf and fgets? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-13T00:22:42.001Z | Help Write Code | v2 | null | null | null | How do you turn a makefile into a linked list? |
63c6489e5f004bf4898cfe23 | 2023-03-13T00:24:10.663Z | Help Write Code | v2 | null | null | null | How do you write a function to parse a makefile? |
63c6489e5f004bf4898cfe23 | 2023-03-14T03:47:17.952Z | Help Write Code | v2 | null | null | null | How do you set a struct member to point to another struct? |
63c6489e5f004bf4898cfe23 | 2023-03-14T03:49:09.385Z | General Question | v2 | How do you allocate memory for the struct and assign the pointer to the struct member?
| null | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-14T11:57:39.368Z | Question from Code | v2 | What is the output of this code if it runs with no error? |
int x = 5;
void handler(int sig) {
x += 3;
fprintf(stderr, "inside %d ", x);
}
int main() {
fprintf(stderr, "start ");
struct sigaction act;
act.sa_handler = handler;
act.sa_flags = 0;
sigemptyset(&act.sa_mask);
sigaction(SIGINT, &act, NULL);
x += 2;
fprintf(stderr, "outside %d", x);
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-03-14T12:00:13.827Z | Question from Code | v2 | What does the program above (from part 1) print to stderr if the user presses Ctrl+C at the moment when the program is at position A?
|
int x = 5;
void handler(int sig) {
x += 3;
fprintf(stderr, "inside %d ", x);
}
int main() {
fprintf(stderr, "start ");
struct sigaction act;
act.sa_handler = handler;
act.sa_flags = 0;
sigemptyset(&act.sa_mask);
sigaction(SIGINT, &act, NULL);
x += 2;
fprintf(stderr, "outside %d", x);
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-03-14T13:14:09.570Z | Explain Code | v2 | null | int x = 5;
void handler(int sig) {
x += 3;
fprintf(stderr, "inside %d ", x);
}
int main() {
fprintf(stderr, "start ");
struct sigaction act;
act.sa_handler = handler;
act.sa_flags = 0;
sigemptyset(&act.sa_mask);
sigaction(SIGINT, &act, NULL);
x += 2;
fprintf(stderr, "outside %d", x);
return 0;
}
| null | null |
63c6489e5f004bf4898cfe23 | 2023-03-15T02:44:23.385Z | General Question | v2 | How do you get rid of "\r\n" from fgets? | null | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-15T05:04:14.000Z | Help Write Code | v2 | null | null | null | How do you write a function to parse a makefile given the following function header: Rule *parse_file(FILE *fp)?
|
63c6489e5f004bf4898cfe23 | 2023-03-15T05:06:54.410Z | Help Write Code | v2 | null | null | null | How do you write a function to parse a makefile using fgets and strtok when given the following function header: Rule *parse_file(FILE *fp)? |
63c6489e5f004bf4898cfe23 | 2023-03-15T05:16:51.954Z | Help Write Code | v2 | null | null | null | How do you write a function to parse a makefile using fgets and strtok when given the following function header: Rule *parse_file(FILE *fp) and the function uses the Action struct with members, char **args; and struct action_node *next_act, the Dependency struct with members Rule *rule, struct Dependency *next_dep, and Rule struct with members: char *target, Dependency *dependencies, Action *actions, and struct rule_node *next_rule. |
63c6489e5f004bf4898cfe23 | 2023-03-15T05:21:05.737Z | Help Write Code | v2 | null | null | null | How do you write a function to parse a makefile using fgets and strtok when given the following function header: Rule *parse_file(FILE *fp) and the function uses the Action struct with members, char **args; and struct action_node *next_act, the Dependency struct with members Rule *rule, struct Dependency *next_dep, and Rule struct with members: char *target, Dependency *dependencies, Action *actions, and struct rule_node *next_rule. |
63c6489e5f004bf4898cfe23 | 2023-03-16T14:21:09.586Z | Question from Code | v2 | Is this the correct way to use pointers for a linked list? | prev_dep = curr_dep;
curr_dep = curr_dep->next_dep;
prev_dep->next_dep = curr_dep; | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-16T14:24:32.878Z | Question from Code | v2 | Is this the correct way to use pointers for a linked list?
| prev_dep->next_dep = curr_dep->next_dep;
curr_dep = curr_dep->next_dep; | null | null |
63c6489e5f004bf4898cfe23 | 2023-03-16T16:46:43.054Z | General Question | v2 | How can you set value to a pointer in a struct without using malloc? | null | null | null |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.