Submission #318467

#	Time	Username	Problem	Language	Result	Execution time	Memory
318467		dufu	Paprike (COI18_paprike)	C++14	100 / 100	83 ms	19940 KiB

paprike

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

#define int long long

int ans, k;
int f[100005] = {};

int dfs(vector<vector<int>> &m, vector<int> &w, int p){
	int sum = w[p];
	vector<int> down;
	for (int i : m[p]){
		if (i != f[p]){
			f[i] = p;
			down.emplace_back(dfs(m, w, i));
			sum += down.back();
		}
	}
	sort(down.begin(), down.end());
	for (int i = down.size() - 1; sum > k; --i){
		sum -= down[i];
		++ans;
	}
//	cout << p << ' ' << sum << '\n';
	return sum;
}

main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	int n;
	cin >> n >> k;
	vector<int> w(n + 1);
	for (int i = 1; i <= n; ++i) cin >> w[i];
	
	vector<vector<int>> m(n + 1);
	
	for (int i = 0; i < n - 1; ++i){
		int a, b;
		cin >> a >> b;
		m[a].emplace_back(b);
		m[b].emplace_back(a);
	}
	ans = 0;
	
	dfs(m, w, 1);
	cout << ans << '\n';
}

Compilation message (stderr)

paprike.cpp:28:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   28 | main(){
      |      ^

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 27 / 27
• Subtask 4: 49 / 49