Submission #765975

#	Time	Username	Problem	Language	Result	Execution time	Memory
765975		yusuf12360	Power Plant (JOI20_power)	C++14	0 / 100	0 ms	212 KiB

power

#include<bits/stdc++.h>
using namespace std;
int ans=2;
vector<int> res;
vector<vector<int>> adj;
string s;
void dfs1(int u=0, int p=-1) {
	res[u]=s[u]-'0';
	for(int pp : adj[u]) {
		if(pp==p) continue;
		dfs1(pp, u);
		if(s[pp]=='1') res[u]++;
		else res[u]+=res[pp];
	}
}
void dfs2(int u=0, int p=-1, int to_p=0) {
	ans=max(ans, res[u]+to_p-2*(s[u]=='1'));
	for(int pp : adj[u]) {
		if(pp==p) continue;
		if(s[u]=='1') dfs2(pp, u, 1);
		else dfs2(pp, u, res[u]-res[pp]);
	}
}
int main() {
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	int n; cin >> n;
	res.resize(n); adj.resize(n);
	while(--n) {
		int u, v; cin >> u >> v; --u; --v;
		adj[u].push_back(v);
		adj[v].push_back(u);}
	cin >> s;
	dfs1();
	dfs2();
	cout << ans << '\n';
	return 0;
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53