Submission #573464

#	Time	Username	Problem	Language	Result	Execution time	Memory
573464		GusterGoose27	Fireworks (APIO16_fireworks)	C++11	7 / 100	5 ms	7380 KiB

fireworks

#include <bits/stdc++.h>

#define pii pair<int, int> 
#define ll long long

using namespace std;

const int MAXN = 3e5;
vector<pii> edges[MAXN]; // node,  cost
int parent[MAXN];
int lval[MAXN]; // inclusive
int rval[MAXN]; // inclusive
ll cost[MAXN];
int n;

void dfs(int s = 0) {
	int m = edges[s].size();
	if (m == 0) {
		cost[s] = 0;
		lval[s] = 0;
		rval[s] = 0;
		return;
	}
	for (pii e: edges[s]) {
		dfs(e.first);
	}
	vector<int> change_pos;
	ll at0 = 0;
	for (pii e: edges[s]) {
		change_pos.push_back(e.second+lval[e.first]);
		change_pos.push_back(e.second+rval[e.first]);
		at0 += lval[e.first]+cost[e.first]+e.second;
	}
	sort(change_pos.begin(), change_pos.end());
	for (int i = 0; i < m; i++) {
		at0 -= change_pos[i];
	}
	cost[s] = at0;
	lval[s] = change_pos[m-1];
	rval[s] = change_pos[m];
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int a, b; cin >> a >> b; n = a+b;
	for (int i = 0; i < n-1; i++) {
		int x, c;
		cin >> x >> c;
		parent[i+1] = x-1;
		edges[x-1].push_back(pii(i+1, c));
	}
	dfs();
	cout << cost[0] << "\n";
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45