Submission #1455119

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Source Code Expand

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

using ll = long long int;

vector<int> tree[110];
int jewel[110] = {};
int f[110] = {};

int solve(int p){
    if(f[p]){
        return 0;
    }
    
    f[p] = true;
    
    int res = 0;
    
    for(const int & next : tree[p]){
        res += solve(next);
    }
    
    if(jewel[p] || res != 0){
        res += 1;
    }
    
    return res;
}

int main(void){
    
    int n,x;
    cin >> n >> x;
    
    for(int i = 0; i < n; i++){
        cin >> jewel[i+1];
    }
    for(int i = 0; i < n-1; i++){
        int a,b;
        cin >> a >> b;
        tree[a].push_back(b);
        tree[b].push_back(a);
    }
    
    cout << max(0,solve(x)-1) * 2 << endl;
}

Submission Info

Judge Result