Submission #868650

#	Time	Username	Problem	Language	Result	Execution time	Memory
868650		12345678	Power Plant (JOI20_power)	C++17	0 / 100	1 ms	4956 KiB

power

#include <bits/stdc++.h>
 
using namespace std;
 
const int nx=2e5+5;
int n, u, v, dp1[nx], dp2[nx];
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);
}
 
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<<max({dp1[1], dp2[1], 0});
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53