11729_하노이탑_이동_순서_중요.cpp

#include <cstdio>
#include <vector>
#include <utility>
#include<iostream>

using namespace std;

vector<pair<int, int> > v;

void hanoi(int n, int from, int by, int to) {
	if (n == 1) v.push_back(make_pair(from, to));
	else {
		hanoi(n - 1, from, to, by);
		v.push_back(make_pair(from, to));
		hanoi(n - 1, by, from, to);
	}
}
int main() {

	int n;
	cin >> n;
	hanoi(n, 1, 2, 3);
	printf("%ld\n", v.size());
	for (int i = 0; i < v.size(); i++) printf("%d %d\n", v[i].first, v[i].second);

	return 0;
}