Submission #427596

#	Time	Username	Problem	Language	Result	Execution time	Memory
427596		davi_bart	Power Plant (JOI20_power)	C++17	100 / 100	235 ms	30848 KiB

power

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define fi first
#define se second
#define ld long double
#define pb push_back
int N;
string c;
vector<int> v[200010];
pair<int,int> ans(int pos,int prec){
    vector<pair<int,int> > k;
    for(int x:v[pos]){
        if(x==prec)continue;
        k.pb(ans(x,pos));
    }
    pair<int,int> ma={0,0};//at most 1 in line,most 2 in line
    if(c[pos]=='1'){
        for(auto [a,b]:k){
            ma.fi+=a;
            ma.se=max({ma.se,a+1,b});
        }
        ma.fi--;
        ma.fi=max(ma.fi,(int)1);
    }else{
        for(auto [a,b]:k){
            ma.fi+=a;
            ma.se=max(ma.se,b);
        }
    }
    //cout<<pos<<" "<<ma.fi<<" "<<ma.se<<endl;
    return ma;
}
signed main(){
	ios::sync_with_stdio(false);cin.tie(0);
    cin>>N;
    for(int i=0;i<N-1;i++){
        int a,b;
        cin>>a>>b;
        a--;b--;
        v[a].pb(b);
        v[b].pb(a);
    }
    cin>>c;
    auto k=ans(0,-1);
    cout<<max(k.fi,k.se)<<endl;
}

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