Submission #39874

#	Time	Username	Problem	Language	Result	Execution time	Memory
39874		aome	Fireworks (APIO16_fireworks)	C++14	100 / 100	289 ms	77056 KiB

fireworks

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

const int N = 300005;

struct Node {
	long long startingValue;
	long long startingSlope;
	priority_queue<long long> pq;
};

int n, m, c[N], p[N];
vector<int> G[N];
Node a[N];

void dfs(int u) {
	if (u > n) return;
	int mx = 0;
	for (auto v : G[u]) {
		dfs(v);
		if (!mx || a[v].pq.size() > a[mx].pq.size()) mx = v;
	}
	swap(a[mx], a[u]);
	for (auto v : G[u]) {
		if (v == mx) continue;
		while (a[v].pq.size()) {
			a[u].pq.push(a[v].pq.top()), a[v].pq.pop();
		}
		a[u].startingValue += a[v].startingValue;
		a[u].startingSlope += a[v].startingSlope;
	}
	while (a[u].startingSlope + a[u].pq.size() > 1) a[u].pq.pop();
	long long x1 = a[u].pq.top(); a[u].pq.pop();
	long long x0 = a[u].pq.top(); a[u].pq.pop();
	a[u].startingValue += c[u];
	a[u].pq.push(x0 + c[u]), a[u].pq.push(x1 + c[u]);
}

int main() {
	ios::sync_with_stdio(false);
	cin >> n >> m;
	for (int i = 2; i <= n + m; ++i) {
		cin >> p[i] >> c[i];
		G[p[i]].push_back(i);
	}
	for (int i = n + 1; i <= n + m; ++i) {
		a[i].startingSlope = -1;
		a[i].startingValue = c[i];
		a[i].pq.push(c[i]), a[i].pq.push(c[i]);
	}
	dfs(1);
	vector<long long> v;
	while (a[1].pq.size()) {
		v.push_back(a[1].pq.top()), a[1].pq.pop();
	}
	reverse(v.begin(), v.end());
	long long cur = 0;
	long long curSlope = a[1].startingSlope;
	long long res = a[1].startingValue;
	// cout << curSlope << ' ' << res << '\n';
	// for (auto i : v) cout << i << ' '; cout << '\n';
	for (int i = 0; i < v.size(); ++i) {
		res += (v[i] - cur) * curSlope, curSlope++, cur = v[i];
	}
	cout << res;
}

Compilation message (stderr)

fireworks.cpp: In function 'int main()':
fireworks.cpp:62:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < v.size(); ++i) {
                    ^

• Subtask 1: 7 / 7
• Subtask 2: 19 / 19
• Subtask 3: 29 / 29
• Subtask 4: 45 / 45