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

typedef struct pax {
    char** arr;
} arrpack;

char* concat(const char *s1, const char *s2)
{
    char *result = malloc(strlen(s1) + strlen(s2) + 1);
    strcpy(result, s1);
    strcat(result, s2);
    return result;
}

void printAllKLengthRec(arrpack* packer, char set[], char prefix[],
                                    int n, int k, int* counter)
{
    if (k == 0)
    {
        int cnt = *counter;
        strcpy(packer->arr[cnt], prefix);

        *counter = *counter + 1;
        return;
    }
    for (int i = 0; i < n; i++)
    {
        char str2[2];
        str2[0] = set[i];
        str2[1] = '\0';
        char* newPrefix = concat(prefix, str2);
        printAllKLengthRec(packer, set, newPrefix, n, k - 1, counter);

    }

}

void printAllKLength(arrpack* packer, char set[], int k,int n)
{
    int counter = 0;
    printAllKLengthRec(packer, set, "", n, k,&counter);
}

int main(void)
{
    char set[52];
    for(int i=0;i<52;i++) {
        if(i<26)
            set[i] = i+'a';
        else
            set[i] = i-26+'A';
    }
    int n=52;
    int k=5;
    arrpack packer;
    size_t combinations = pow(n,k);
    packer.arr = (char **)malloc(combinations*sizeof(char*));
    for (int i=0; i<combinations; i++)
         packer.arr[i] = (char *)malloc(k+1);


    printAllKLength(&packer, set, k, n);

    for(int i=0;i<combinations;i++) {
        packer.arr[i];
        gchar  *sha512;
        sha512 = g_compute_checksum_for_string(G_CHECKSUM_SHA512, packer.arr[i], k);

        printf("%s",packer.arr[i]);
        g_free(sha512);
    }



    return 0;
}