Submission #1129562

#	Time	Username	Problem	Language	Result	Execution time	Memory
1129562		Newtonabc	Power Plant (JOI20_power)	C++20	100 / 100	224 ms	31936 KiB

power

#include<bits/stdc++.h>
using namespace std;
const int N=2e5+10;
vector<int> adj[N];
int dp[N][2];
string s;
void dfs(int u,int p=-1){
    int mx=0;
    dp[u][0]=0;
    dp[u][1]=s[u]-'0';
    for(int v:adj[u]){
        if(v==p) continue;
        dfs(v,u);
        dp[u][0]+=max({dp[v][1]-(s[v]-'0')*2,dp[v][0]});
        dp[u][1]=max({dp[u][1],dp[v][0]+s[u]-'0',dp[v][1]-1});
    }
    dp[u][0]=max(s[u]-'0',dp[u][0]-(s[u]-'0'));
    if(s[u]-'0'==0) dp[u][1]=0;
}
int main(){
    int n;
    cin>>n;
    for(int i=0;i<n-1;i++){
        int a,b;
        cin>>a >>b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    cin>>s;
    s=" "+s;
    int root;
    for(int i=1;i<=n;i++){
        if(s[i]=='1'){
            dfs(i);
            root=i;
            break;
        }
    }
    int ans=0;
    for(int i=1;i<=n;i++){
        ans=max({ans,dp[i][0],dp[i][1]});
    }
    cout<<ans;
   
}

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