Submission #818537

#	Time	Username	Problem	Language	Result	Execution time	Memory
818537		vjudge1	Power Plant (JOI20_power)	C++17	100 / 100	135 ms	28988 KiB

power

#include<bits/stdc++.h>

using namespace std;
using ll = long long;

const int N = 2e5 + 10;
vector<int> g[N];
int dp[N];
int n;
string s;
int res;
void dfs(int v, int p) {
    int sum = 0, mx = 0;
    for(int to : g[v]) {
        if(to == p) continue;
        dfs(to, v);
        mx = max(mx, dp[to]);
        sum += max(dp[to], 0);
    }
    dp[v] = max(s[v - 1] - '0', sum - (s[v - 1] - '0'));
    res = max(res, dp[v]);
    if(s[v - 1] == '1') 
        res = max(res, mx + 1);
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin >> n;
    for(int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    cin >> s;
    dfs(1, 1);
    // for(int i = 1; i <= n; i++) {
    //     cout << dp[i] << ' ';
    // }
    // cout << '\n';
    cout << res;
}

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