Submission #1693654


Source Code Expand

#include <bits/stdc++.h>
#define int long long
#define N 100010
using namespace std;
const int INF = 1LL<<55;
const int mod = (1e9)+7;
const double EPS = 1e-8;
const double PI = 6.0 * asin(0.5);
template<class T> T Max(T &a,T b){return a=max(a,b);}
template<class T> T Min(T &a,T b){return a=min(a,b);}
vector<int> G[N];
int num[N];

int ans;
int can(int pos,int par){
  int sum = 0;
  for(int to:G[pos]) if(to!=par) sum += num[to];
  if(sum < num[pos]) return 0;
  if(sum == num[pos]) return 1;

  int target = num[pos];
  int a = 0;
  for(int to:G[pos]){
    if(to == par) continue;
    int b = min(abs(sum - target), min(a,num[to]) );
    target -= b;
    sum -= b * 2;
    assert(sum>=0 && target >=0);
    if(sum == target){
      num[pos] = target;
      return 1;
    }
    a = abs(a - num[to]);
  }
  return 0;
}

int check(int pos,int par){
  if(G[pos].size() == 1) return 1;
  
  for(int to:G[pos]){
    if(to == par) continue;
    if(check(to,pos) == 0) return ans = 0;
  }
  return ans = can(pos,par);
}
signed main(){
  int n;
  cin>>n;
  for(int i=0;i<n;i++) cin>>num[i];
  
  for(int i=0,a,b;i<n-1;i++){
    cin>>a>>b;  a--,b--;
    G[a].push_back(b);
    G[b].push_back(a);
  }

  ans = 1;
  check(0,-1);
  cout<<(ans? "YES":"NO")<<endl;
  return 0;
}

Submission Info

Submission Time
Task C - Cleaning
User haji
Language C++14 (GCC 5.4.1)
Score 0
Code Size 1330 Byte
Status WA
Exec Time 125 ms
Memory 10496 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 700
Status
AC × 1
WA × 2
AC × 30
WA × 21
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 112 ms 7168 KB
in10.txt AC 114 ms 7168 KB
in11.txt AC 123 ms 9728 KB
in12.txt AC 125 ms 9728 KB
in13.txt AC 102 ms 10496 KB
in14.txt AC 101 ms 9984 KB
in15.txt WA 3 ms 2560 KB
in16.txt AC 3 ms 2560 KB
in17.txt AC 3 ms 2560 KB
in18.txt WA 3 ms 2560 KB
in19.txt AC 104 ms 7040 KB
in2.txt AC 105 ms 7168 KB
in20.txt WA 105 ms 7040 KB
in21.txt AC 106 ms 7168 KB
in22.txt WA 102 ms 7168 KB
in23.txt WA 102 ms 7040 KB
in24.txt WA 112 ms 7168 KB
in25.txt AC 3 ms 2560 KB
in26.txt AC 115 ms 7040 KB
in27.txt WA 113 ms 7168 KB
in28.txt WA 3 ms 2560 KB
in29.txt WA 90 ms 7040 KB
in3.txt AC 106 ms 7168 KB
in30.txt AC 3 ms 2560 KB
in31.txt WA 107 ms 7168 KB
in32.txt AC 106 ms 7168 KB
in33.txt AC 104 ms 7040 KB
in34.txt AC 104 ms 7040 KB
in35.txt WA 106 ms 7040 KB
in36.txt WA 105 ms 7168 KB
in37.txt AC 4 ms 2688 KB
in38.txt AC 106 ms 7168 KB
in39.txt AC 105 ms 7168 KB
in4.txt AC 102 ms 7040 KB
in40.txt WA 103 ms 7040 KB
in41.txt WA 102 ms 7040 KB
in42.txt WA 102 ms 7168 KB
in43.txt WA 102 ms 7168 KB
in44.txt AC 106 ms 7168 KB
in45.txt WA 101 ms 7168 KB
in5.txt AC 106 ms 7168 KB
in6.txt AC 109 ms 7040 KB
in7.txt AC 98 ms 6656 KB
in8.txt AC 25 ms 3584 KB
in9.txt AC 118 ms 7168 KB
sample1.txt AC 3 ms 2560 KB
sample2.txt WA 3 ms 2560 KB
sample3.txt WA 3 ms 2560 KB