HackerRank Strings: Making Anagrams - I'm trying to refresh my C knowledge. This program returns an integer representing the minimum total characters that must be deleted to make the strings anagrams.

making_anagrams.c

int Count(char* s, char c) {
  // Count variable
  int res = 0;

  for (int i = 0; i < strlen(s); i++)

    // checking character in string
    if (s[i] == c)
      res++;

  return res;
}

// Complete the makeAnagram function below.
int makeAnagram(char* a, char* b) {
    int count = 0;
    int ai = 0;
    int bi = 0;
    for (int i = (int)'a'; i <= (int)'z'; i++)
    {
      ai = Count(a, (char)i);
      bi = Count(b, (char)i);
      count += abs(ai - bi);
    }

    return count;
}