Submission #2211534
Source Code Expand
#include <iostream> #include <cstdio> #include <cstring> #define N 100005 using namespace std; typedef long long ll; struct edge{ int k,next; }e[N<<1]; int n,home[N],cnt=-1,w[N],D=1; ll f[N],a[N]; void add(int x,int y){ cnt++; e[cnt].k=y; e[cnt].next=home[x]; home[x]=cnt; } void dfs(int k,int F){ if(w[k]==1){ f[k]=a[k];return; } ll sum=0; for(int i=home[k];~i;i=e[i].next) if(e[i].k!=F){ dfs(e[i].k,k); if(!D) return; if(f[e[i].k]>a[k]){ D=0;return; } sum+=f[e[i].k]; } if(sum<a[k]){ D=0;return; } if(sum>a[k]+a[k]){ D=0;return; } f[k]=a[k]+a[k]-sum; } int main(){ memset(home,-1,sizeof(home)); scanf("%d",&n); for(int i=1;i<=n;i++) scanf("%lld",&a[i]); if(n==2){ if(a[1]!=a[2]) puts("NO"); else puts("YES"); return 0; } for(int i=1,x,y;i<n;i++){ scanf("%d%d",&x,&y); add(x,y);add(y,x); w[x]++;w[y]++; } int F; for(int i=1;i<=n;i++) if(w[i]>1){ F=i; dfs(i,0); break; } if(D&&!f[F]) puts("YES"); else puts("NO"); return 0; }
Submission Info
Submission Time | |
---|---|
Task | C - Cleaning |
User | liumy2010 |
Language | C++14 (GCC 5.4.1) |
Score | 700 |
Code Size | 1051 Byte |
Status | AC |
Exec Time | 36 ms |
Memory | 8192 KB |
Compile Error
./Main.cpp: In function ‘int main()’: ./Main.cpp:41:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ ./Main.cpp:42:43: 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("%lld",&a[i]); ^ ./Main.cpp:49:22: 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 | 700 / 700 | ||||
Status |
|
|
Set Name | Test Cases |
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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 | 35 ms | 4096 KB |
in10.txt | AC | 35 ms | 4096 KB |
in11.txt | AC | 34 ms | 7424 KB |
in12.txt | AC | 35 ms | 7424 KB |
in13.txt | AC | 32 ms | 8192 KB |
in14.txt | AC | 31 ms | 7552 KB |
in15.txt | AC | 1 ms | 640 KB |
in16.txt | AC | 1 ms | 640 KB |
in17.txt | AC | 1 ms | 640 KB |
in18.txt | AC | 1 ms | 640 KB |
in19.txt | AC | 33 ms | 4224 KB |
in2.txt | AC | 35 ms | 4096 KB |
in20.txt | AC | 30 ms | 3456 KB |
in21.txt | AC | 30 ms | 3328 KB |
in22.txt | AC | 30 ms | 4096 KB |
in23.txt | AC | 31 ms | 4096 KB |
in24.txt | AC | 33 ms | 4096 KB |
in25.txt | AC | 1 ms | 640 KB |
in26.txt | AC | 31 ms | 3328 KB |
in27.txt | AC | 31 ms | 3328 KB |
in28.txt | AC | 1 ms | 640 KB |
in29.txt | AC | 27 ms | 3328 KB |
in3.txt | AC | 35 ms | 4096 KB |
in30.txt | AC | 1 ms | 640 KB |
in31.txt | AC | 30 ms | 4096 KB |
in32.txt | AC | 33 ms | 4096 KB |
in33.txt | AC | 34 ms | 4096 KB |
in34.txt | AC | 35 ms | 4096 KB |
in35.txt | AC | 34 ms | 4096 KB |
in36.txt | AC | 35 ms | 4096 KB |
in37.txt | AC | 2 ms | 640 KB |
in38.txt | AC | 32 ms | 4096 KB |
in39.txt | AC | 30 ms | 4096 KB |
in4.txt | AC | 35 ms | 4096 KB |
in40.txt | AC | 33 ms | 4096 KB |
in41.txt | AC | 33 ms | 4096 KB |
in42.txt | AC | 36 ms | 4096 KB |
in43.txt | AC | 32 ms | 4096 KB |
in44.txt | AC | 34 ms | 4096 KB |
in45.txt | AC | 35 ms | 4096 KB |
in5.txt | AC | 35 ms | 4096 KB |
in6.txt | AC | 35 ms | 4096 KB |
in7.txt | AC | 31 ms | 3840 KB |
in8.txt | AC | 9 ms | 1408 KB |
in9.txt | AC | 35 ms | 4096 KB |
sample1.txt | AC | 1 ms | 640 KB |
sample2.txt | AC | 1 ms | 640 KB |
sample3.txt | AC | 1 ms | 640 KB |