a simple way to generate permutations

permutations

#include <stdio.h>

void print_array(int array[], int n)
{
    int i;

    for (i = 0; i < n; i++) {
        printf("%d%s", array[i], i != n-1 ? " " : "\n");
    }
}

void swap(int *a, int *b)
{
    int t;
    
    t = *a;
    *a = *b;
    *b = t;
}

void permute(int array[], int n, int level)
{
    int i;

    if (level == n-1) {
        print_array(array, n);
        return;
    }

    for (i = level; i < n; i++) {
        swap(&array[i], &array[level]);
        permute(array, n, level + 1);
        swap(&array[i], &array[level]);
    }
}

int main(int argc, char const *argv[])
{
    int a[] = {1, 2, 3, 4, 5};
    permute(a, 5, 0);
    return 0;
}