Submission #1707824

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Source Code Expand

#include "bits/stdc++.h"
using namespace std;
typedef long long LL;
const int INF = 1 << 25;

int main() {
	int N;
	cin >> N;
	int cnt[5] = { 0 };
	for (int i = 0; i < N; i++) {
		int A;
		cin >> A;
		cnt[A]++;
	}
	int ans = cnt[4];
	ans += cnt[3];
	cnt[1] -= min(cnt[1], cnt[3]);
	ans += cnt[2] / 2;
	cnt[2] %= 2;
	ans += cnt[2];
	cnt[1] -= min(cnt[1], cnt[2] * 2);
	ans += cnt[1];
	cout << ans << endl;
}

Submission Info

Judge Result