Submission #287649

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Source Code Expand

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>

using namespace std;

int n,x;
int hs[101];
int ls[101];
int vs[101];
int ps[101];


int main(){
  cin >> n >> x;
  for(int i=1;i<=n;++i){
    cin >> hs[i];
  }
  multimap<int,int> tree;
  for(int i=1;i<n;++i){
    int a,b;
    cin >> a >> b;
    tree.insert(make_pair(a,b));
    tree.insert(make_pair(b,a));
  }

  int node = x;
  queue<int> q;

  q.push(x);
  vs[x] = 1;
  while (!q.empty()){
    int node = q.front();
    if(tree.count(node)==1)
      ls[node] = 1;
    auto search = tree.equal_range(node);
    for(auto i=search.first;i!=search.second;++i){
      if(!vs[i->second]) q.push(i->second);
    }
    vs[node] = 1;
    q.pop();
  }

  queue<int> qq;
  for(int i=0;i<=n;++i){
    if(ls[i]) {
      qq.push(i);
    }
  }

  while(qq.size()){
    int node = qq.front();
    if(!hs[node]){
      ps[node] = 1;
      auto search = tree.equal_range(node);
      for(auto i=search.first;i!=search.second;++i){
        if(!ps[node])
          qq.push(i->second);
      }
    }
    qq.pop();
  }

  int ans = n-1;
  for(int i=1;i<=n;++i)
    if(ps[i]) --ans;

  cout << ans*2 << endl;

}

Submission Info

Judge Result