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

void swap(char* num, int i, int j){
    char temp = num[i];
    num[i] = num[j];
    num[j] = temp;
}

int find_max_index(char *num, size_t num_size){
    for (int i = num_size - 2; i >= 0; i--) {
        if (num[i] < num[i + 1]) {
            return i;
        }
    }
    return -1;
}

int find_index_bigger_element(char *num, size_t num_size, int element){
    for (int i = num_size - 1; i >= 0; i--) {
        if (num[i] > element) {
            return i;
        }
    }
    return -1;
}

void reverse_sequence_part(int begin, char* num, size_t num_size){
    int end = num_size - 1;

    while (begin < end)
    {
        swap(num, begin, end);
        begin++;
        end--;
    }
}

void narajana(int permutation_counter, char *num){
    size_t num_size = strlen(num);
    int index = find_max_index(num, num_size);
    for (; index != -1;) {
        int element = num[index];
        int swapIndex = find_index_bigger_element(num, num_size, element);
        swap(num, index, swapIndex);
        reverse_sequence_part(index, num, num_size);
        printf("%s\n", num);
        index = find_max_index(num, num_size);
    }
}

int main(){
    int permutation_counter = 2;
    char *num = "214";
    narajana(permutation_counter, num);

}