#include <stdio.h>
#include <string.h>

// aab
// aba <- OK
// abb
// aab <- WRONG

int cmpr(char *str1, char *str2) {

    if (str1 == NULL || str2 == NULL) {
        return 0;
    }

    //declarations and initializations of 26-elements arrays,
    //every single alphabetic character with one index assigned
    int tab1[26] = {0}, tab2[26] = {0};
    int i = 0, j = 0;

    //incrementation of specific array's index for str1
    for (; *(str1 + i) != '\0'; ++i) {
        tab1[*(str1 + i) - 'a']++;
    }

    //incrementation of specific array's index for str2
    for (; *(str2 + j) != '\0'; ++j) {
        tab2[*(str2 + j) - 'a']++;
    }

    //validation of both arrays length and memory areas
    if (i == j) {
        if (!memcmp(tab1, tab2, sizeof(tab1))) {
            return 1;
        }
    }
    return 0;
}

int main() {
    printf("%d\n", cmpr("abcdef", "abcfed"));
}