Submission #1612868


Source Code Expand

#include<bits/stdc++.h>
#define N 100005
#define LL long long
using namespace std;
vector<int> G[N];
int n,a[N],d[N],rt;
void GG(){ printf("NO"); exit(0);}
void dfs(int t,int fa)
{
	int i; LL Max=0,x,sum=0;
	if(d[t]==1) return ;
	for(i=0;i<G[t].size();i++)
		if(G[t][i]!=fa) dfs(G[t][i],t);
	for(i=0;i<G[t].size();i++)
		if(G[t][i]!=fa)
			sum+=a[G[t][i]],Max=max(Max,1LL*a[G[t][i]]);
	x=sum-a[t];
	if(x<0||2*x>sum) GG();
	if(Max*2>sum&&x>sum-Max) GG();
	a[t]=sum-2*x;
}
int main()
{
	int i,x,y;
	scanf("%d",&n);
	for(i=1;i<=n;i++) scanf("%d",&a[i]);
	for(i=1;i<n;i++){
		scanf("%d %d",&x,&y);
		G[x].push_back(y),d[x]++;
		G[y].push_back(x),d[y]++;
	  }
	for(i=1;i<=n;i++)
		if(d[i]!=1) rt=i;
	if(rt==0){
		if(a[1]!=a[2]) GG();
		else printf("YES");
		return 0;
	  }
	dfs(rt,0);
	if(a[rt]!=0) GG();
	printf("YES");
	return 0;
}

Submission Info

Submission Time
Task C - Cleaning
User MemorySlices
Language C++14 (GCC 5.4.1)
Score 700
Code Size 872 Byte
Status AC
Exec Time 56 ms
Memory 13568 KB

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:25:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:26:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for(i=1;i<=n;i++) scanf("%d",&a[i]);
                                     ^
./Main.cpp:28:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&x,&y);
                       ^

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 56 ms 6656 KB
in10.txt AC 51 ms 6656 KB
in11.txt AC 53 ms 12416 KB
in12.txt AC 53 ms 11776 KB
in13.txt AC 49 ms 12800 KB
in14.txt AC 53 ms 13568 KB
in15.txt AC 2 ms 2560 KB
in16.txt AC 2 ms 2560 KB
in17.txt AC 2 ms 2560 KB
in18.txt AC 2 ms 2560 KB
in19.txt AC 48 ms 6656 KB
in2.txt AC 49 ms 6656 KB
in20.txt AC 45 ms 6656 KB
in21.txt AC 46 ms 6656 KB
in22.txt AC 47 ms 6656 KB
in23.txt AC 47 ms 6656 KB
in24.txt AC 49 ms 6656 KB
in25.txt AC 2 ms 2560 KB
in26.txt AC 48 ms 6656 KB
in27.txt AC 47 ms 6656 KB
in28.txt AC 2 ms 2560 KB
in29.txt AC 43 ms 6656 KB
in3.txt AC 50 ms 6656 KB
in30.txt AC 2 ms 2560 KB
in31.txt AC 50 ms 6656 KB
in32.txt AC 47 ms 6656 KB
in33.txt AC 51 ms 6656 KB
in34.txt AC 49 ms 6656 KB
in35.txt AC 49 ms 6656 KB
in36.txt AC 45 ms 6656 KB
in37.txt AC 3 ms 2688 KB
in38.txt AC 49 ms 6656 KB
in39.txt AC 50 ms 6656 KB
in4.txt AC 49 ms 6656 KB
in40.txt AC 51 ms 6656 KB
in41.txt AC 49 ms 6656 KB
in42.txt AC 50 ms 6656 KB
in43.txt AC 48 ms 6656 KB
in44.txt AC 49 ms 6656 KB
in45.txt AC 49 ms 6656 KB
in5.txt AC 49 ms 6656 KB
in6.txt AC 50 ms 6656 KB
in7.txt AC 44 ms 6144 KB
in8.txt AC 12 ms 3584 KB
in9.txt AC 49 ms 6656 KB
sample1.txt AC 2 ms 2560 KB
sample2.txt AC 2 ms 2560 KB
sample3.txt AC 2 ms 2560 KB