Submission #623060

#	Time	Username	Problem	Language	Result	Execution time	Memory
623060		Mahdi	Power Plant (JOI20_power)	C++17	100 / 100	183 ms	32444 KiB

power

#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#define all(v) v.begin(), v.end()
#define F first
#define S second
typedef long long ll;
typedef pair<int, int> pii;
const int N=2e5+5;
int n, dp[N], pd[N];
vector<int>g[N];
string s;

void dfs(const int &v, const int &p=-1){
    for(int u: g[v]){
        if(u!=p){
            dfs(u, v);
            pd[v]+=pd[u];
            if(s[v]=='1')
                dp[v]=max(dp[v], pd[u]+1);
            dp[v]=max(dp[v], dp[u]);  
        }
    }
    if(s[v]=='1'){
        --pd[v];
        pd[v]=max(pd[v], 1);
    }
    dp[v]=max(dp[v], pd[v]);
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>n;
    for(int i=1;i<n;++i){
        int u, v;
        cin>>u>>v;
        g[--u].push_back(--v);
        g[v].push_back(u);
    }
    cin>>s;
    dfs(0);
    cout<<dp[0]<<'\n';
}

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