Submission #246828

#	Time	Username	Problem	Language	Result	Execution time	Memory
246828		vioalbert	Fireworks (APIO16_fireworks)	C++14	100 / 100	286 ms	71032 KiB

fireworks

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

const int N = 3e5+5;
struct slope {
	ll m, c;
	priority_queue<ll> pq;
	slope& operator+=(slope& ot) {
		m += ot.m, c += ot.c;
		if(pq.size() < ot.pq.size()) swap(pq, ot.pq);
		while(!ot.pq.empty())
			pq.push(ot.pq.top()), ot.pq.pop();
		return *this;
	}
};
slope f[N];
ll cost[N];
int n, m;
vector<int> adj[N];


void read() {
	cin >> n >> m;
	for(int i = 2; i <= n+m; i++) {
		int p; cin >> p >> cost[i];
		adj[p].push_back(i);
	}
}

void dfs(int u) {
	if(adj[u].empty()) {
		f[u].m = 1, f[u].c = -cost[u];
		f[u].pq.push(cost[u]);
		f[u].pq.push(cost[u]);
		return;
	}

	for(int v : adj[u]) {
		dfs(v);
		f[u] += f[v];
	}

	//reducing largest slope
	while(f[u].m > 1) {
		f[u].m -= 1;
		f[u].c += f[u].pq.top();
		f[u].pq.pop();
	}

	//adding parent edge
	ll x = f[u].pq.top() + cost[u]; f[u].pq.pop();
	ll y = f[u].pq.top() + cost[u]; f[u].pq.pop();
	f[u].pq.push(x); f[u].pq.push(y);
	f[u].c -= cost[u];
}

void solve() {
	dfs(1);
	ll ans = f[1].m * f[1].pq.top() + f[1].c;
	cout << ans << '\n';
}

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	read();
	solve();
	return 0;
}

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