Submission #958892

#	Time	Username	Problem	Language	Result	Execution time	Memory
958892		pcc	Power Plant (JOI20_power)	C++17	100 / 100	116 ms	28956 KiB

power

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

#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>

const int mxn = 2e5+10;
int dp[mxn];
string s;
vector<int> tree[mxn];
int N;
int ans = 0;

void dfs(int now,int par){
	dp[now] = s[now]-'0';
	int mx = 0,down = 0;
	for(auto nxt:tree[now]){
		if(nxt == par)continue;
		dfs(nxt,now);
		mx = max(mx,dp[nxt]);
		down += max(dp[nxt],0);
	}
	ans = max({mx+dp[now],down-dp[now],ans});
	dp[now] = max(dp[now],down-dp[now]);
	return;
}

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>N;
	for(int i = 1;i<N;i++){
		int a,b;
		cin>>a>>b;
		tree[a].push_back(b);
		tree[b].push_back(a);
	}
	cin>>s;
	s = "#"+s;
	dfs(1,1);
	cout<<ans<<'\n';
	return 0;
}

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