1. Why pointer to custom struct doesn't work in that code?
2. Why I'm getting warning in that line with p->x = x?
3. Why I'm getting second warning in line with strcpy\_s?

```
#include <stdlib.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

typedef struct sptr {
    int x;
    char* s;
    struct sptr* next;
} ptr;

void add(ptr* p, int x, const char* s) {
    ptr* o = p;
    p = (ptr*) malloc(sizeof(ptr));
    p->x = x; // warning
    p->s = (char*)malloc(20 * sizeof(char));
    strcpy_s(p->s, 20, (char*)s); // warning
    p->next = o;
}

void show(ptr* p) {
    ptr* o = p;
    while (o != NULL) {
        printf("%d %s\n", o -> x, o -> s);
        o = o->next;
    }
}

int main() {
    ptr* p = NULL;

    add(p, 5, "xcvxvxv");
    add(p, 7, "adadad");
    show(p);

    return 0;
}

```