Submission #236754

#	Time	Username	Problem	Language	Result	Execution time	Memory
236754		meatrow	Remittance (JOI19_remittance)	C++17	100 / 100	446 ms	52192 KiB

remittance

#pragma GCC optimize("O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;

ll div(vector<ll>& num, int n) {
	ll res = 0;
	for (int i = 35; i >= 0; i--) {
		vector<ll> den(num.size());
		fill(den.begin() + i, den.begin() + n + i, 1);
		bool ok = true;
		for (int j = num.size() - 1; j >= 0; j--) {
			if (num[j] > den[j]) {
				break;
			}
			if (num[j] < den[j]) {
				ok = false;
			}
		}
		if (!ok) continue;
		res += 1LL << i;
		for (int j = 0; j + 1 < num.size(); j++) {
			num[j] -= den[j];
			if (num[j] < 0) {
				num[j] += 2;
				num[j + 1]--;
			}
		}
	}
	return res;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n;
	cin >> n;
	vector<ll> a(n), b(n);
	vector<ll> lul(n + 123);
	for (int i = 0; i < n; i++) {
		cin >> a[i] >> b[i];
		lul[i] = a[i] - b[i];
	}
	// t[n - 1] = sigma(2^i * (a[i] - b[i])) / (2^n - 1)
	for (int i = 0; i + 1 < lul.size(); i++) {
		lul[i + 1] += lul[i] / 2;
		lul[i] %= 2;
		if (lul[i] < 0) {
			lul[i] += 2;
			lul[i + 1]--;
		}
	}
	if (find(lul.begin(), lul.end(), -1) != lul.end()) {
		cout << "No\n";
		return 0;
	}
	ll kek = div(lul, n);
	if (find(lul.begin(), lul.end(), 1) != lul.end()) {
		cout << "No\n";
		return 0;
	}
	ll heh = 0;
	for (int i = 0; i < n; i++) {
		heh += a[i];
		heh /= 2;
	}
	if (n < 35) {
		ll pw = 1LL << n; 
		ll huh = heh / pw;
		while (huh) {
			heh += huh;
			huh /= pw;
		}
	}
	if (heh < kek) {
		cout << "No\n";
		return 0;
	}
	a[n - 1] -= 2 * kek;
	a[0] += kek;
	for (int i = 0; i < n - 1; i++) {
		if (a[i] < b[i] || (a[i] - b[i]) % 2) {
			cout << "No\n";
			return 0;
		}
		ll mem = (a[i] - b[i]) / 2;
		a[i] -= mem * 2;
		a[i + 1] += mem; 
	}
	if (a[n - 1] != b[n - 1]) {
		cout << "No\n";
	} else {
		cout << "Yes\n";
	}
	return 0;
}

Compilation message (stderr)

remittance.cpp: In function 'll div(std::vector<long long int>&, int)':
remittance.cpp:26:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 0; j + 1 < num.size(); j++) {
                   ~~~~~~^~~~~~~~~~~~
remittance.cpp: In function 'int main()':
remittance.cpp:50:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i + 1 < lul.size(); i++) {
                  ~~~~~~^~~~~~~~~~~~

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