백준 n과 m

#include <iostream>
using namespace std;


int n, m;
int path[10];
void run(int lev, int now) {
	if (lev>1&&path[lev - 1] == path[lev - 2])return;
	if (lev == m) {
		for (int i = 0; i < m; i++) {
			cout << path[i];
		}
		cout << endl;
		return;
	}
	for (int i =now; i <= n; i++) {
		path[lev] = i;
		run(lev + 1, i);
		path[lev] = 0;
	}
}
int main() {
	cin >> n >> m;
	run(0, 1);

	return 0;
}

[출력]
12
13
14
23
24
34