Submission #1293279

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;


int n, x, h[105];
vector<int> v[105];

int dfs(int x, int pre) {
    int ret = 0;
    for (int i : v[x]) {
        if (i == pre) continue;

        int a = dfs(i, x);
        if (a > 0 || h[i])
            ret += a + 1;
    }
    return ret;
}

int main() {
    cin >> n >> x;
    --x;
    for (int i = 0; i < n; ++i) {
        cin >> h[i];
    }
    for (int i = 0; i < n - 1; ++i) {
        int a, b;
        cin >> a >> b;
        --a;
        --b;
        v[a].emplace_back(b);
        v[b].emplace_back(a);
    }
    cout << (dfs(x, -1) * 2) << "\n";
    return 0;
}

Submission Info

Judge Result