Submission #868649

#	Time	Username	Problem	Language	Result	Execution time	Memory
868649		12345678	Power Plant (JOI20_power)	C++17	100 / 100	99 ms	29584 KiB

power

#include <bits/stdc++.h>

using namespace std;

const int nx=2e5+5;
int n, u, v, dp1[nx], dp2[nx], ans;
vector<int> d[nx];
string s;

void dfs(int u, int p)
{

    for (auto v:d[u])
    {
        if (v==p) continue;
        dfs(v, u);
        if (s[u-1]=='1') dp1[u]+=dp1[v], dp2[u]=max(dp2[u], dp1[v]+1);
        else dp1[u]+=max(dp1[v], dp2[v]-2), dp2[u]=max(dp2[u], dp2[v]);
    }
    if (s[u-1]=='1') dp1[u]=max(1, dp1[u]-1), dp2[u]=max(dp2[u], 1);
    ans=max({ans, dp1[u], dp2[u]});
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    for (int i=1; i<n; i++) cin>>u>>v, d[u].push_back(v), d[v].push_back(u);
    cin>>s;
    dfs(1, 1);
    cout<<ans;
}

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