Submission #671128

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Source Code Expand

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

vector<int> g[100];
int h[100], visited[100];

int dfs(int v)
{
    int res=0;
    visited[v]++;
    for(int u: g[v]) if (!visited[u]) res+=dfs(u);
    return res ? res+1 : h[v];
}

int main()
{
    int n, x; cin>>n>>x;
    for(int i=0; i<n; ++i) cin>>h[i];

    for(int i=1; i<n; ++i) {
        int a, b; cin>>a>>b;
        --a, --b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    visited[--x]++;
    int res=0;
    for(int v: g[x]) res+=dfs(v);
    cout<<res*2<<endl;
}

Submission Info

Judge Result