Submission #1199486

#	Time	Username	Problem	Language	Result	Execution time	Memory
1199486		A_M_Namdar	Divide and conquer (IZhO14_divide)	C++20	100 / 100	21 ms	7056 KiB

divide

#include <bits/stdc++.h>
using namespace std;

const long long N = 1e5 + 10;
long long n, x[N], d[N], g[N], a[N], ps[N], ps2[N], maxi[N << 2];

void build(long long l, long long r, long long id) {
	if (r - l == 1) {
		maxi[id] = ps[l];
		return;
	}
	long long mid = (l + r) / 2;
	build(l, mid, id << 1), build(mid, r, id << 1 | 1);
	maxi[id] = max(maxi[id << 1], maxi[id << 1 | 1]);
}

long long get(long long l, long long r, long long v, long long id) {
	if (r - l == 1) return r;
	long long mid = (l + r) / 2;
	if (maxi[id << 1 | 1] >= v) return get(mid, r, v, id << 1 | 1);
	return get(l, mid, v, id << 1);
}

void input() {
	cin >> n;
	for (long long i = 0; i < n; i++) {
		cin >> x[i] >> g[i] >> d[i];
		ps2[i + 1] = ps2[i] + g[i];
		if (i > 0) {
			a[i] = -(x[i] - x[i - 1]) + d[i];
			ps[i] = ps[i - 1] + a[i];
		}
		else {
			a[i] = ps[i] = d[i];
		}
	}
}

void solve() {
	build(0, n, 1);
	long long ans = 0;
	for (long long i = 0; i < n; i++) {
		long long tmp = get(0, n, ps[i] - d[i], 1);
		ans = max(ans, ps2[tmp] - ps2[i]);
	}
	cout << ans;
}

int main() {
	ios:: sync_with_stdio(0), cin.tie(0), cout.tie(0);
	input();
	solve();
}

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52