Submission #1293258

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Source Code Expand

#include<bits/stdc++.h>

using namespace std;

int N, X;
bool H[100];
vector< int > g[100];

int rec(int idx, int par = -1)
{
  int ret = 0;
  for(auto &to : g[idx]) {
    if(to == par) continue;
    auto get = rec(to, idx);
    if(~get) ret += get + 2;
  }
  if(ret == 0) return (H[idx] - 1);
  return (ret);
}

int main()
{
  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);
  }
  cout << max(0, rec(--X)) << endl;
}

Submission Info

Judge Result