Ask about printing strings using the C language recursive function.

aaa
aab
aba
abb
baa
bab
bba
bbb

 if (n > 1) {       
    while (len > i) {
         for (i = my_pow(2, n); i < 3*my_pow(2, n-1); i++)
            strcat(dic[i], "a");            
        for (i = 3* my_pow(2, n-1); i < my_pow(2, n+1); i++)
            strcat(dic[i], "b");        
    }   
}

#pragma warning (disable : 4996)
#include<stdio.h>
#include<string.h>
#include<stdlib.h>

int my_pow(int base, int exp) {

    //You must create your own power function.

    int i, j;
    j = base;
    for (i = 0; i < exp - 1; i++)
        j = j * base;

    return j;
}

void Dicstr(char **dic, int n, int len)
{

    char ab[2][2] = { "a", "b" };
    int i = 0;
    int k;

    if (n == 1) {
        i = 0;
        while (i < len) {
            for (k = 0; k < 2; k++) {
                strcat(dic[i], ab[k]);
                i++;
            }
        }
        return;
    }
    if (n > 1) {
        for (i = 0; i < my_pow(2, n - 1); i++)
            strcat(dic[i], "a");
        for (i = my_pow(2, n - 1); i < my_pow(2, n); i++)
            strcat(dic[i], "b");
    }
    if (n > 1) {
        while (len > i) {
            for (i = my_pow(2, n); i < 3*my_pow(2, n-1); i++)
                strcat(dic[i], "a");
            for (i = 3* my_pow(2, n-1); i < my_pow(2, n+1); i++)
                strcat(dic[i], "b");
        }
    }
    if (n > 1)
        Dicstr(dic, n - 1, len);
}

void strPrint(char **str, int num) {

    int i;

    for (i = 0; i < my_pow(2, num); i++)
        printf("%s\n", str[i]);

}

int main(void) {

    int num = 0;
    int i;
    char **new;
    int len = 0;

    scanf("%d", &num);
    len = my_pow(2, num);

    new = (char **)calloc(len, sizeof(char *); //2D character array dynamic assignment
    for (i = 0; i < len; i++)
        new[i] = (char *)calloc(len, sizeof(char));

    Dicstr(new, num, len); // Functions that are arranged in dictionary order
    strPrint(new, num); //Function to output

    for (i = 0; i < len; i++) { //dynamic deallocation
        free(new[i]);
    }
    free(new);

    return 0;
}