DFS exercise

#include <stdio.h>
 
void DFS(int n, int d, int s, int arr[])
{
    if(d == n)
    {
        int last_ck = 1;
        int j = 10-n;
        for(int i=0; i < d; i++, j++)
        {
            printf("%d", arr[i]);
            if(arr[i] != j)
                last_ck = 0;
        }
        if(!last_ck)
            printf(", ");
        return ;
    }
 
    arr[d] = s;
    for(int i=s; i <= 10-n+d; i++)
    {
        DFS(n, d+1, i+1, arr);
        arr[d+1] = '\0';
        if(d+1 == n) break;
    }
}
 
void ft_print_combn(int n)
{
    int arr[10] = {0};
    // stage 0
    for(int i=0; i <= 10-n; i++)
    {
        DFS(n, 0, i, arr);
    }
}
 
int main(int argc, char **argv)
{
    int n;
    printf("input: ");
    scanf("%d", &n);
    ft_print_combn(n);
    puts(" ");
}