Permutations.c

#include <stdio.h>
#include <stdbool.h>

int main() {
  const char *A = "powerful";
  const int sizeA = 8;
  const char *B = "fulewopr";
  const int sizeB = 8;

  int lettersA[26];
  int lettersB[26];

  for (int i = 0; i < 26; ++i) { 
    lettersA[i] = 0;
    lettersB[i] = 0;
  }

  bool permutation = true;
  if (sizeA != sizeB) {
    permutation = false;
  }
  else {
    for (int i = 0; i < sizeA; ++i) {
      ++lettersA[A[i] - 'a'];
      ++lettersB[B[i] - 'a'];
    }

    for (int i = 0; i < 26; ++i) {
      if (lettersA[i] != lettersB[i]) permutation = false;
    }
  }

  printf("%s\n", permutation ? "Strings are permutations" : "Strings are not permutations");

  return 0;
}