Submission #1258902

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Source Code Expand

/*
#pragma region GNUC
//https://yukicoder.me/wiki/auto_vectorization
#ifdef __GNUC__
#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#endif
#pragma endregion
*/
#define _USE_MATH_DEFINES
#pragma region include
#include <iostream>
#include <iomanip>
#include <stdio.h>

#include <sstream>
#include <algorithm>
#include <cmath>

#include <string>
#include <cstring>
#include <vector>
#include <tuple>

#include <queue>
#include <complex>
#include <set>
#include <map>
#include <stack>
#include <list>

#include <fstream>
#include <random>
//#include <time.h>
#include <ctime>
#pragma endregion //#include
/////////
#define REP(i, x, n) for(int i = x; i < n; ++i)
#define rep(i,n) REP(i,0,n)
/////////
#pragma region typedef
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
#pragma endregion //typedef
////定数
const int INF = (int)1e9;
const LL MOD = (LL)1e9+7;
const LL LINF = (LL)1e18;
const double PI = acos(-1.0);
const double EPS = 1e-9;
/////////
using namespace::std;

vector<int> dist(100,-1);
vector<bool> visit(100,false);
vector<int> H(100);
vector< vector<int> > Gra(100);

int dfs(int v,int D){
	int ans = 0;
	visit[v] = true;
	bool flag = false;
	if( H[v] == 1 ){
		flag = true;//往復分,スタート地点は消しておく
	}
	int size = Gra[v].size();
	int res = 0;
	for(int i=0;i<size;++i){
		int to = Gra[v][i];
		if( visit[to] ) continue;
		res = dfs(to,D+1);
		if(res){
			flag = true;
		}
		ans += res;
	}
	if( flag ){
		ans += 2;
	}
	return ans;
}


void solve(){
	int N,start;
	cin >> N >> start;
	--start;
	for(int i=0;i<N;++i){
		cin >> H[i];
	}
	H[start] = 0;

	for(int i=0;i<N-1;++i){
		int a,b;
		cin >> a >> b;
		--a;--b;
		Gra[a].push_back(b);
		Gra[b].push_back(a);
	}
	
	int ans = dfs(start,0);
	if( ans > 0 ){
		ans -=2;
	}
	cout << ans << endl;
}

#pragma region main
signed main(void){
	std::cin.tie(0);
	std::ios::sync_with_stdio(false);
	std::cout << std::fixed;//小数を10進数表示
	cout << setprecision(16);//小数点以下の桁数を指定//coutとcerrで別	
	
	solve();
}
#pragma endregion //main()

Submission Info

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