Submission #516585

#	Time	Username	Problem	Language	Result	Execution time	Memory
516585		Cross_Ratio	Power Plant (JOI20_power)	C++14	100 / 100	154 ms	27148 KiB

power

#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<vector<int> > adj;
int DP[200005];
bool type[200005];
int ans = 0;
void dfs(int c, int p) {
    int sum = 0;
    DP[c] = type[c] ? 1 : 0;
    for(int n : adj[c]) {
        if(n==p) continue;
        dfs(n,c);
        sum += DP[n];
        ans = max(ans, DP[n] + DP[c]);
    }
    DP[c] = max(DP[c],sum-DP[c]);
    ans = max(ans, DP[c]);
}
signed main() {
    cin.sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int N;
    cin >> N;
    int i;
    adj.resize(N);
    for(i=0;i<N-1;i++) {
        int a, b;
        cin >>a  >> b;
        adj[a-1].push_back(b-1);
        adj[b-1].push_back(a-1);
    }
    string s;
    cin >> s;
    for(i=0;i<N;i++) type[i] = s[i] == '1';
    dfs(0, -1);
    cout << ans;
}

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