Submission #488551

#	Time	Username	Problem	Language	Result	Execution time	Memory
488551		alextodoran	Power Plant (JOI20_power)	C++17	47 / 100	1587 ms	12668 KiB

power

/**
 ____ ____ ____ ____ ____
||a |||t |||o |||d |||o ||
||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|

**/

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N_MAX = 200000;

int N;

vector <int> adj[N_MAX + 2];

bool plant[N_MAX + 2];

int dp[N_MAX + 2];

void dfs (int u, int parent = -1) {
    dp[u] = 0;
    for (int v : adj[u]) {
        if (v != parent) {
            dfs(v, u);
            dp[u] += dp[v];
        }
    }
    if (plant[u] == true) {
        dp[u] = max(dp[u] - 1, 1);
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> N;
    for (int i = 1; i <= N - 1; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    string str;
    cin >> str;
    for (int u = 1; u <= N; u++) {
        plant[u] = (str[u - 1] == '1');
    }

    int cntPlants = 0;
    for (int u = 1; u <= N; u++) {
        cntPlants += plant[u];
    }

    int answer = min(cntPlants, 2);
    for (int r = 1; r <= N; r++) {
        dfs(r);
        answer = max(answer, dp[r]);
    }

    cout << answer << "\n";

    return 0;
}

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