Programe to check wether the given word is anagram or not in C

#include <stdio.h>

int check_anagram(char [], char []);

int main()
{
   char a[100], b[100];
   int flag;

   printf("Enter first stringn");
   gets(a);

   printf("Enter second stringn");
   gets(b);

   flag = check_anagram(a, b);

   if (flag == 1)
      printf(""%s" and "%s" are anagrams.n", a, b);
   else
      printf(""%s" and "%s" are not anagrams.n", a, b);

   return 0;
}

int check_anagram(char a[], char b[])
{
   int first[26] = {0}, second[26] = {0}, c = 0;

   while (a[c] != '')
   {
      first[a[c]-'a']++;
      c++;
   }

   c = 0;

   while (b[c] != '')
   {
      second[b[c]-'a']++;
      c++;
   }

   for (c = 0; c < 26; c++)
   {
      if (first[c] != second[c])
         return 0;
   }

   return 1;
}

Output

Enter first string
act

Enter second string
cat

act and cat are anagrams