Submission #685350

#	Time	Username	Problem	Language	Result	Execution time	Memory
685350		flappybird	Remittance (JOI19_remittance)	C++17	100 / 100	217 ms	51972 KiB

remittance

#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define MAX 1020200
#define MAXS 20
#define INF 1000000000000000001
#define bb ' '
#define ln '\n'
#define Ln '\n'
ll A[MAX];
ll B[MAX];
ll d[MAX];
ll X[MAX];
int N;
bool chk(ll x0) {
	X[N] = x0;
	int i;
	for (i = N - 1; i >= 0; i--) {
		X[i] = 2 * X[i + 1] + d[i + 1];
		if (X[i] < 0) return false;
		if (X[i] > 1e18) return false;
	}
	for (i = 0; i < N; i++) if (X[i] < 0) return false;
	return X[0] == X[N];
}
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	cin >> N;
	ll i;
	for (i = 0; i < N; i++) cin >> A[i] >> B[i], d[i] = B[i] - A[i];
	d[N] = d[0];
	ll sum = 0;
	for (i = 1; i <= min(60, N); i++) sum -= d[N - i + 1] >> i;
	if (sum < -101010 || sum > 1e10) {
		cout << "No" << ln;
		return 0;
	}
	if (N <= 20) {
		sum <<= N;
		sum /= ((1ll << N) - 1ll);
	}
	int c = 0;
	for (i = sum - 500; i <= sum + 500; i++) {
		if (chk(i)) {
			c = 1;
			break;
		}
	}
	if (!c) {
		cout << "No" << ln;
		return 0;
	}
	while (1) {
		int c = 0;
		for (i = 0; i < N; i++) {
			if (X[i] && A[i] > 1) {
				c = 1;
				ll x = min(X[i], A[i] / 2);
				X[i] -= x;
				A[(i + 1) % N] += x;
				A[i] -= x * 2;
			}
		}
		if (!c) break;
	}
	int no = 0;
	for (i = 0; i < N; i++) if (X[i]) no = 1;
	if (!no) cout << "Yes" << ln;
	else cout << "No" << ln;
}

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