Submission #1987418


Source Code Expand

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define _CRT_SECURE_NO_WARNINGS
#include <vector>
#include <iostream>
#include <string.h>
#include <set>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <string>
using namespace std;

typedef double LD;
typedef long long LL;
typedef pair<int, int> PII;
#define MP make_pair
#define PB push_back
#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
#define RFOR(i,b,a) for(int i = (b) - 1; i >= (a); --i)
#define REP(i, t) FOR(i,0,t)
#define ALL(a) a.begin(), a.end()
#define SZ(a) (int)((a).size())

const LL MOD = 1000000007;
const int INF = 1e9;
const LL LINF = 1LL * INF * INF;
const int MAXN = 100007;
const LD EPS = 1e-7;

int A[MAXN];
vector <int> G[MAXN];
bool used[MAXN], flag = true;

void dfs(int v)
{
	used[v] = true;
	int cnt = 0, m = 0;
	LL s = 0;
	REP(i, SZ(G[v]))
	{
		int to = G[v][i];
		if (!used[to])
		{
			dfs(to);
			if (A[to])
				++cnt;
			s += A[to];
			m = max(m, A[to]);
		}
	}
	if (cnt)
	{
		if (2 * A[v] < s || A[v] > s || 2 * m > s)
			flag = false;
		A[v] = 2 * A[v] - s;
	}
}

int main()
{
	ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	//freopen("In.txt", "r", stdin);
	int n, r;
	cin >> n;
	REP(i, n)
		cin >> A[i];
	if (n == 2)
	{
		cout << (A[0] == A[1] ? "YES" : "NO");
		return 0;
	}
	REP(i, n - 1)
	{
		int a, b;
		cin >> a >> b;
		--a; --b;
		G[a].push_back(b);
		G[b].push_back(a);
	}
	REP(i, n)
		if (SZ(G[i]) > 1)
			r = i;
	dfs(r);
	cout << (flag && A[r] == 0 ? "YES" : "NO");
	//cout << endl; system("pause");
	return 0;
}

Submission Info

Submission Time
Task C - Cleaning
User vjudge3
Language C++14 (GCC 5.4.1)
Score 0
Code Size 1599 Byte
Status WA
Exec Time 49 ms
Memory 13312 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 700
Status
AC × 1
WA × 2
AC × 33
WA × 18
Set Name Test Cases
Sample sample1.txt, sample2.txt, sample3.txt
All sample1.txt, sample2.txt, sample3.txt, in1.txt, in10.txt, in11.txt, in12.txt, in13.txt, in14.txt, in15.txt, in16.txt, in17.txt, in18.txt, in19.txt, in2.txt, in20.txt, in21.txt, in22.txt, in23.txt, in24.txt, in25.txt, in26.txt, in27.txt, in28.txt, in29.txt, in3.txt, in30.txt, in31.txt, in32.txt, in33.txt, in34.txt, in35.txt, in36.txt, in37.txt, in38.txt, in39.txt, in4.txt, in40.txt, in41.txt, in42.txt, in43.txt, in44.txt, in45.txt, in5.txt, in6.txt, in7.txt, in8.txt, in9.txt, sample1.txt, sample2.txt, sample3.txt
Case Name Status Exec Time Memory
in1.txt WA 46 ms 6272 KB
in10.txt WA 45 ms 6272 KB
in11.txt WA 47 ms 12160 KB
in12.txt WA 47 ms 11520 KB
in13.txt AC 44 ms 12544 KB
in14.txt AC 44 ms 13312 KB
in15.txt AC 3 ms 2560 KB
in16.txt AC 3 ms 2560 KB
in17.txt AC 3 ms 2560 KB
in18.txt AC 3 ms 2560 KB
in19.txt AC 45 ms 6272 KB
in2.txt WA 45 ms 6272 KB
in20.txt AC 46 ms 6272 KB
in21.txt AC 46 ms 6272 KB
in22.txt AC 45 ms 6272 KB
in23.txt AC 45 ms 6272 KB
in24.txt AC 45 ms 6272 KB
in25.txt AC 3 ms 2560 KB
in26.txt AC 47 ms 6272 KB
in27.txt AC 47 ms 6272 KB
in28.txt AC 3 ms 2560 KB
in29.txt AC 43 ms 6272 KB
in3.txt WA 45 ms 6272 KB
in30.txt AC 3 ms 2560 KB
in31.txt AC 49 ms 6272 KB
in32.txt AC 45 ms 6272 KB
in33.txt WA 45 ms 6272 KB
in34.txt WA 45 ms 6272 KB
in35.txt AC 45 ms 6272 KB
in36.txt AC 45 ms 6272 KB
in37.txt AC 3 ms 2688 KB
in38.txt AC 45 ms 6272 KB
in39.txt AC 45 ms 6272 KB
in4.txt WA 45 ms 6272 KB
in40.txt AC 45 ms 6272 KB
in41.txt AC 45 ms 6272 KB
in42.txt AC 45 ms 6272 KB
in43.txt AC 45 ms 6272 KB
in44.txt AC 45 ms 6272 KB
in45.txt AC 45 ms 6272 KB
in5.txt WA 45 ms 6272 KB
in6.txt WA 45 ms 6272 KB
in7.txt WA 40 ms 5888 KB
in8.txt WA 12 ms 3456 KB
in9.txt WA 45 ms 6272 KB
sample1.txt WA 3 ms 2560 KB
sample2.txt AC 3 ms 2560 KB
sample3.txt WA 3 ms 2560 KB