Submission #618218

#	Time	Username	Problem	Language	Result	Execution time	Memory
618218		penguinhacker	Power Plant (JOI20_power)	C++17	100 / 100	148 ms	28896 KiB

power

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

#define ll long long
#define ar array

const int mxN=2e5;
int n, ans, dp[mxN];
string s;
vector<int> adj[mxN];

void dfs(int u=0, int p=-1) {
	int mx=0;
	dp[u]='0'-s[u];
	for (int v : adj[u])
		if (v!=p) {
			dfs(v, u);
			dp[u]+=max(dp[v], 0);
			mx=max(mx, dp[v]);
		}
	ans=max(ans, mx+(s[u]=='1'));
	if (s[u]=='1')
		dp[u]=max(dp[u], 1);
	ans=max(ans, dp[u]);
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	for (int i=1; i<n; ++i) {
		int u, v;
		cin >> u >> v, --u, --v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	cin >> s;
	dfs();
	cout << ans;
	return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53