백준 12852번 - C++

#include <bits/stdc++.h>
using namespace std;

int D[1000002];
int pre[1000002];
int n;
int main(void) {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	D[1] = 0;

	for (int i = 2; i <= n; i++) {
		D[i] = D[i - 1] + 1;
		pre[i] = i - 1;
		if (i % 2 == 0&& D[i]>D[i/2]+1) {
			D[i] = min(D[i], D[i / 2] + 1);
			pre[i] = i / 2;
		}
		if (i % 3 == 0&&D[i]>D[i/3]+1) {
			D[i] = min(D[i], D[i / 3] + 1);
			pre[i] = i / 3;
		}
	}
	cout << D[n]<<'\n';
	int cur = n;
	while (true) {
		cout << cur << ' ';
		if (cur == 1) break;
		cur = pre[cur];
	}
}