Submission #3207851

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Source Code Expand

#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <unordered_map>

using namespace std;
typedef long long int ll;
typedef pair<int, int> P;

vector<int> g[100];
int d[100];
bool used[100];
bool nuee[100];

void dfs(int i){
	used[i]=1;
	for(auto y:g[i]){
		if(!used[y]){
			dfs(y);
          if(nuee[y]){
			nuee[i]=1;
			d[i]+=(d[y]+1);
          }
		}
	}
}

int main()
{
	int n, x;
	cin>>n>>x;
	x--;
	for(int i=0; i<n; i++){
		int h; cin>>h;
		if(h==1) nuee[i]=1;
	}
	for(int i=0; i<n-1; i++){
		int a, b; cin>>a>>b;
		a--; b--;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	dfs(x);
	cout<<2*d[x]<<endl;
	return 0;
}

Submission Info

Judge Result