Submission #270392

#	Time	Username	Problem	Language	Result	Execution time	Memory
270392		islingr	Remittance (JOI19_remittance)	C++17	100 / 100	286 ms	28752 KiB

remittance

#include <iostream>
using namespace std;

#define rep(i, a, b) for (auto i = (a); i < (b); ++i)

const int N = 1 << 20;
int a[N], b[N];

#pragma GCC optimize ("trapv")

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n; cin >> n;
	rep(i, 0, n) cin >> a[i] >> b[i];
	bool fine = false;
	rep(i, 0, n) if (b[i] != 0) fine = true;
	if (!fine) {
		rep(i, 0, n) if (a[i] != 0) return cout << "No", 0;
		return cout << "Yes", 0;
	}
	bool flow = true;
	while (flow) {
		flow = false;
		rep(i, 0, n) {
			if (a[i] <= b[i]) continue;
			flow = true;
			int del = (a[i] - b[i] + 1) / 2;
			a[i] -= 2 * del;
			a[(i + 1) % n] += del;
		}
	}
	cout << ([&]() {
		rep(i, 0, n) if (a[i] != b[i]) return false;
		return true;
	}() ? "Yes" : "No");
}

• Subtask 1: 15 / 15
• Subtask 2: 40 / 40
• Subtask 3: 45 / 45