Submission #787681

#	Time	Username	Problem	Language	Result	Execution time	Memory
787681		winter0101	Power Plant (JOI20_power)	C++14	100 / 100	115 ms	28836 KiB

power

#include<bits/stdc++.h>
using namespace std;
#define all(fl) fl.begin(),fl.end()
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define lb lower_bound
#define ub upper_bound
#define sz(a) (int)a.size()
#define pii pair<int,int>
#define pli pair<long long,int>
#define gcd __gcd
#define lcm(x,y) x*y/__gcd(x,y)
#define pil pair<int,long long>
vector<int>a[200009];
int f[200009];
string s;
int ans=0;
void dfs(int u,int par){
if (s[u]=='1'){
    f[u]=1;
}
int sum=0;
for (auto v:a[u]){
    if (v==par)continue;
    dfs(v,u);
    if (s[u]=='1'){
        ans=max(ans,f[v]+1);
    }
    sum+=f[v];
}
if (s[u]=='1')sum--;
f[u]=max(f[u],sum);
ans=max(ans,f[u]);
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("temp.INP","r",stdin);
    //freopen("temp.OUT","w",stdout);
    int n;
    cin>>n;
    for1(i,1,n-1){
    int u,v;
    cin>>u>>v;
    a[u].pb(v);
    a[v].pb(u);
    }
    cin>>s;
    s=" "+s;
    dfs(1,0);
    cout<<ans;
}

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