Submission #849773

#	Time	Username	Problem	Language	Result	Execution time	Memory
849773		Abito	Power Plant (JOI20_power)	C++17	100 / 100	183 ms	26704 KiB

power

#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define ep insert
#define endl '\n'
#define elif else if
#define pow pwr
#define sqrt sqrtt
#define int long long
#define y1 YONE
typedef unsigned long long ull;
using namespace std;
const int N=2e5+5;
int n,dp[N],ans;
vector<int> adj[N];
bool a[N];
int rec(int node,int p){
    //int s=bool(p);
    dp[node]=0;
    for (auto u:adj[node]) if (u!=p) dp[node]+=rec(u,node);
    if (adj[node].size()<=1) dp[node]+=a[node];
    else dp[node]-=a[node];
    return dp[node]=max(dp[node],(int)a[node]);
}
void dfs(int node,int p){
    if (p) dp[p]=max(dp[p]-dp[node],(int)a[p]);
    dp[node]=max(dp[node]+dp[p],(int)a[node]);
    ans=max(ans,dp[node]);
    for (auto u:adj[node]) if (u!=p) dfs(u,node);
    return;
}
int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    cin>>n;
    for (int i=1;i<n;i++){
        int x,y;cin>>x>>y;
        adj[x].pb(y);adj[y].pb(x);
    }for (int i=1;i<=n;i++){char c;cin>>c;a[i]=c-'0';}
    rec(1,0);
    dfs(1,0);
    cout<<ans<<endl;
    return 0;
}

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