Submission #695782

#	Time	Username	Problem	Language	Result	Execution time	Memory
695782		ethening	Self Study (JOI22_ho_t2)	C++17	100 / 100	496 ms	11460 KiB

Main

#include "bits/stdc++.h"
#include <functional>
using namespace std;
using ll = long long;
using pii = pair<int, int>;

int main() {
	cin.tie(0)->sync_with_stdio(0);
	int n, m;
	cin >> n >> m;
	vector<ll> a(n), b(n);
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	for (int i = 0; i < n; i++) {
		cin >> b[i];
	}
	for (int i = 0; i < n; i++) {
		a[i] = max(a[i], b[i]);
	}

	auto check = [&](ll mid) -> bool {
		ll freeLesson = 0;
		for (int i = 0; i < n; i++) {
			ll numLesson = mid / a[i] + ((mid % a[i] == 0) ? 0 : 1);
			// cout << "@@@" << i << " " << a[i] << " " << numLesson << endl;
			if (numLesson < m) {
				freeLesson += m - numLesson;
			}
		}
		// cout << mid << " " << freeLesson << endl;
		for (int i = 0; i < n; i++) {
			ll numLesson = mid / a[i] + ((mid % a[i] == 0) ? 0 : 1);
			if (numLesson > m) {
				ll stillNeed = max(0ll, mid - m * a[i]);
				freeLesson -= stillNeed / b[i] + ((stillNeed % b[i] == 0) ? 0 : 1);
			}
			if (freeLesson < 0) return false;
		}
		return true;
	};

	ll l = 0;
	ll r = 1e18;
	while (l <= r) {
		ll mid = (l + r) / 2;
		if (check(mid)) {
			l = mid + 1;
		}
		else {
			r = mid - 1;
		}
	}
	cout << r << "\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 25 / 25
• Subtask 3: 27 / 27
• Subtask 4: 29 / 29
• Subtask 5: 9 / 9