Interview Question

solution.c

#include <stdio.h>

int main()
{
  printf("%i\n", solution("asdfdsa\0"));
  printf("%i\n", solution("asddsa\0"));
  printf("%i\n", solution("a\0"));
  printf("%i\n", solution("ac\0"));
}

int solution(char *S)
{
  int counter[26] = {0};
  int i = 0;
  int odd = 0;
  while (*S != '\0')
  {
    printf("%c", *S);
    counter[*S-'a']++;
    S++;
  }
  printf("%c", '\n');
  for (i = 0; i < 26; i++)
  {
    if (counter[i] % 2 != 0 && odd) return 0;
    else if (counter[i] % 2 != 0) odd = 1;
  }
  return 1;
}