Submission #1837240


Source Code Expand

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <sstream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cctype>
#include <cstring>
#include <vector>
#include <list>
#include <queue>
#include <deque>
#include <stack>
#include <map>
#include <set>
#include <algorithm>
#include <iterator>
#include <bitset>
#include <ctime>
#include<complex>
using namespace std;

#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 ITER(it,a) for (__typeof(a.begin()) it = a.begin(); it != a.end(); it++)
#define FILL(a,value) memset(a, value, sizeof(a))

#define SZ(a) (int)a.size()
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;

const double PI = acos(-1.0);
const int INF = 1000 * 1000 * 1000 + 7;
const LL LINF = INF * (LL)INF;

const int MAX = 1000 * 100 + 47;

int n;
int A[MAX];
vector<int> g[MAX];
vector<int> L[MAX];

void no()
{
	cout << "NO" << endl;
	exit(0);
}

LL dfs(int v, int p)
{
	if (SZ(g[v]) == 1 && v != 0) return A[v];
	FOR(i, 0, SZ(g[v]))
	{
		int to = g[v][i];
		if (to == p) continue;
		L[v].push_back(dfs(to, v));
	}

	LL s = 0;
	int maxx = -INF;
	FOR(i, 0, SZ(L[v]))
	{
		s += L[v][i];
		maxx = max(maxx, L[v][i]);
	}

	if (A[v] > s) no();
	LL all = s;
	if (maxx > s - maxx)
	{
		all = 2 * (s - maxx);
	}

	if (2 * (s - A[v]) > all) no();
	
	LL totop = s - 2 * (s - A[v]);
	if (v == 0)
	{
		if (SZ(g[v]) == 1 && A[v] != totop) no();
		if (SZ(g[v]) != 1 && totop != 0) no();
	}

	return totop;
}

int main()
{
	//freopen("in.txt", "r", stdin);
	//freopen("out.txt", "w", stdout);
	ios::sync_with_stdio(false); cin.tie(0);
	cin >> n;
	FOR(i, 0, n) cin >> A[i];
	FOR(i, 0, n - 1)
	{
		int a, b;
		cin >> a >> b;
		a--; b--;
		g[a].push_back(b);
		g[b].push_back(a);
	}

	dfs(0, 0);
	cout << "YES" << endl;
	return 0;
}

Submission Info

Submission Time
Task C - Cleaning
User vjudge4
Language C++14 (Clang 3.8.0)
Score 700
Code Size 1942 Byte
Status AC
Exec Time 301 ms
Memory 20992 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 700 / 700
Status
AC × 3
AC × 51
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 AC 259 ms 10240 KB
in10.txt AC 254 ms 10240 KB
in11.txt AC 289 ms 19200 KB
in12.txt AC 301 ms 19200 KB
in13.txt AC 235 ms 20992 KB
in14.txt AC 242 ms 19712 KB
in15.txt AC 3 ms 4992 KB
in16.txt AC 3 ms 4992 KB
in17.txt AC 3 ms 4992 KB
in18.txt AC 3 ms 4992 KB
in19.txt AC 254 ms 9344 KB
in2.txt AC 263 ms 10240 KB
in20.txt AC 256 ms 8576 KB
in21.txt AC 259 ms 8576 KB
in22.txt AC 265 ms 9088 KB
in23.txt AC 266 ms 10240 KB
in24.txt AC 264 ms 10240 KB
in25.txt AC 3 ms 4992 KB
in26.txt AC 279 ms 8576 KB
in27.txt AC 284 ms 8576 KB
in28.txt AC 3 ms 4992 KB
in29.txt AC 224 ms 8576 KB
in3.txt AC 264 ms 10240 KB
in30.txt AC 3 ms 4992 KB
in31.txt AC 258 ms 9984 KB
in32.txt AC 258 ms 8960 KB
in33.txt AC 259 ms 10240 KB
in34.txt AC 258 ms 10240 KB
in35.txt AC 262 ms 10240 KB
in36.txt AC 261 ms 10240 KB
in37.txt AC 5 ms 4992 KB
in38.txt AC 264 ms 9728 KB
in39.txt AC 258 ms 9984 KB
in4.txt AC 263 ms 10240 KB
in40.txt AC 252 ms 8960 KB
in41.txt AC 248 ms 9088 KB
in42.txt AC 259 ms 10240 KB
in43.txt AC 258 ms 10240 KB
in44.txt AC 274 ms 10112 KB
in45.txt AC 264 ms 10240 KB
in5.txt AC 263 ms 10240 KB
in6.txt AC 265 ms 10240 KB
in7.txt AC 230 ms 9600 KB
in8.txt AC 63 ms 6144 KB
in9.txt AC 261 ms 10240 KB
sample1.txt AC 3 ms 4992 KB
sample2.txt AC 3 ms 4992 KB
sample3.txt AC 3 ms 4992 KB