text: #include <stdio.h>
  #include <stdlib.h>
  
  int compute_vowel_count(const char *p);
  
  int main(void) {
      char sentence[BUFSIZ];
      printf("Enter a sentence: ");
      if (fgets(sentence, BUFSIZ - 1, stdin) == NULL)
          exit(1);
      printf("Sentence contains %d vowels.\n", compute_vowel_count(sentence));
  
      return 0;
  }
  
  int compute_vowel_count(const char *p) {
      int count = 0;
      while (*p) {
          if (*p == 'a' || *p == 'e' || *p == 'i' || *p == 'o' || *p == 'u') {
              count++;
          }
          p++;
      }
      return count;
  }
  