순열 알고리즘 (Permutation)

#include <iostream>
using namespace std;
 
#define swap(a,b,tmp) tmp=a; a=b; b=tmp;
 
int n,num[1001],tmp;
 
void perm(int* num, int start, int end) {
    if (start == end) {
        for (int i = 0; i < n; i++) {
            cout << num[i] << " ";
        }
        cout << '\n';
        return;
    }
 
    for (int i = start; i <= end; i++) {
        swap(num[start], num[i],tmp);
        perm(num, start + 1, end);
        swap(num[start], num[i], tmp);
    }
}
 
int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> num[i];
    }
    perm(num, 0, n - 1);
 
    return 0;
}