Submission #1693501


Source Code Expand

#include <algorithm>
#include <cstdio>

const int N=100005;
int fst[N],deg[N],a[N],tot=0;

struct Edge{
	int to,nxt;
}e[N*2];

void addedge(int x,int y){
	e[++tot].to=y;e[tot].nxt=fst[x];fst[x]=tot;deg[y]++;
}

bool dfs(int x,int father){
	if (deg[x]==1){
		
		return 1;
	}
	int sum=0,mx=0;
	for (int i=fst[x];i;i=e[i].nxt){
		int y=e[i].to;
		if (y!=father){
			if (!dfs(y,x)) return 0;
			sum+=a[y];
			mx=std::max(mx,a[y]);
		}
	}
	a[x]=a[x]*2-sum;
	return (a[x]>=0 && mx*2-sum<=a[x]);
}

int main(){
	int n,root=0;
	scanf("%d\n",&n);
	for (int i=1;i<=n;i++) scanf("%d",&a[i]);
	for (int i=1;i<n;i++){
		int x,y;
		scanf("%d%d",&x,&y);
		addedge(x,y);
		addedge(y,x);
	}
	if (n==2){
		printf(a[1]==a[2]?"YES":"NO");
		return 0;
	}
	for (int i=1;i<=n;i++)
		if (deg[i]>1) root=i;
	if (dfs(root,0) && !a[root]) printf("YES\n");
		else printf("NO\n");
}

Submission Info

Submission Time
Task C - Cleaning
User aufeas
Language C++14 (GCC 5.4.1)
Score 0
Code Size 903 Byte
Status WA
Exec Time 36 ms
Memory 9984 KB

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:35:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d\n",&n);
                  ^
./Main.cpp:36:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for (int i=1;i<=n;i++) scanf("%d",&a[i]);
                                          ^
./Main.cpp:39:22: 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 0 / 700
Status
AC × 3
AC × 47
WA × 4
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 32 ms 2944 KB
in10.txt AC 32 ms 2944 KB
in11.txt AC 36 ms 8832 KB
in12.txt AC 36 ms 8192 KB
in13.txt AC 32 ms 9216 KB
in14.txt AC 33 ms 9984 KB
in15.txt AC 1 ms 128 KB
in16.txt AC 1 ms 128 KB
in17.txt AC 1 ms 128 KB
in18.txt AC 1 ms 128 KB
in19.txt AC 31 ms 2944 KB
in2.txt AC 33 ms 2944 KB
in20.txt AC 29 ms 2944 KB
in21.txt AC 29 ms 2944 KB
in22.txt AC 32 ms 2944 KB
in23.txt WA 32 ms 2944 KB
in24.txt AC 32 ms 2944 KB
in25.txt AC 1 ms 128 KB
in26.txt AC 30 ms 2944 KB
in27.txt AC 30 ms 2944 KB
in28.txt AC 1 ms 128 KB
in29.txt AC 26 ms 2944 KB
in3.txt AC 32 ms 2944 KB
in30.txt AC 1 ms 128 KB
in31.txt WA 32 ms 2944 KB
in32.txt WA 32 ms 2944 KB
in33.txt AC 32 ms 2944 KB
in34.txt AC 32 ms 2944 KB
in35.txt AC 32 ms 2944 KB
in36.txt AC 32 ms 2944 KB
in37.txt AC 1 ms 128 KB
in38.txt AC 32 ms 2944 KB
in39.txt AC 32 ms 2944 KB
in4.txt AC 32 ms 2944 KB
in40.txt AC 32 ms 2944 KB
in41.txt AC 32 ms 2944 KB
in42.txt AC 33 ms 2944 KB
in43.txt AC 30 ms 2944 KB
in44.txt WA 32 ms 2944 KB
in45.txt AC 32 ms 2944 KB
in5.txt AC 32 ms 2944 KB
in6.txt AC 33 ms 2944 KB
in7.txt AC 29 ms 2560 KB
in8.txt AC 8 ms 768 KB
in9.txt AC 33 ms 2944 KB
sample1.txt AC 1 ms 128 KB
sample2.txt AC 1 ms 128 KB
sample3.txt AC 1 ms 128 KB