BOJ 15649 N과 M (1), 순열

#include <iostream>
#include <vector>
using namespace std;
int n, m;
vector<int> v;
bool check[9];
void dfs(int cnt) {
    if (cnt == m) {
        for (int i = 0; i < m; i++) {
            cout << v[i] << " ";
        }
        cout << endl;
        return;
    }
    for (int i = 1; i <= n; i++) {
        if(check[i] == true) continue;
        check[i] = true;
        v.push_back(i);
        dfs(cnt + 1);
        check[i] = false;
        v.pop_back();
    }
}
int main(void) {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> m;
    dfs(0);
}