Submission #1692979
Source Code Expand
#include<cstdio> #include<algorithm> using namespace std; inline int read() { int x;char c; while((c=getchar())<'0'||c>'9'); for(x=c-'0';(c=getchar())>='0'&&c<='9';)x=x*10+c-'0'; return x; } #define MN 100000 struct edge{int nx,t;}e[MN*2+5]; int a[MN+5],h[MN+5],en,r[MN+5],ans; long long s[MN+5],c[MN+5]; inline void ins(int x,int y) { e[++en]=(edge){h[x],y};h[x]=en;++r[x]; e[++en]=(edge){h[y],x};h[y]=en;++r[y]; } void dfs(int x,int fa) { if(r[x]==1){s[x]=c[x]=a[x];return;} for(int i=h[x];i;i=e[i].nx)if(e[i].t!=fa) dfs(e[i].t,x),c[x]+=c[e[i].t]; long long j,k=0; for(int i=h[x];i;i=e[i].nx)if(e[i].t!=fa) { j=a[x]<c[x]?min(c[x]-a[x],min(k,s[e[i].t]>>1)):0; j+=a[x]<c[x]-j?min(c[x]-j-a[x],min(s[x],s[e[i].t]-(j<<1))):0; c[x]-=j;c[fa]-=j;k+=j;s[x]+=s[e[i].t]-(j<<1); } if(a[x]^c[x])ans=1; } int main() { int n=read(),i; for(i=1;i<=n;++i)a[i]=read(); if(n==2){puts(a[1]^a[2]?"NO":"YES");return 0;} for(i=1;i<n;++i)ins(read(),read()); for(i=1;i<=n;++i)if(r[i]>1){dfs(i,0);break;} puts(ans||s[i]?"NO":"YES"); }
Submission Info
Submission Time | |
---|---|
Task | C - Cleaning |
User | ditoly |
Language | C++14 (GCC 5.4.1) |
Score | 0 |
Code Size | 1078 Byte |
Status | WA |
Exec Time | 28 ms |
Memory | 9856 KB |
Judge Result
Set Name | Sample | All | ||||||
---|---|---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 0 / 700 | ||||||
Status |
|
|
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 | 25 ms | 4480 KB |
in10.txt | AC | 21 ms | 4480 KB |
in11.txt | AC | 26 ms | 8832 KB |
in12.txt | AC | 26 ms | 8832 KB |
in13.txt | AC | 21 ms | 9856 KB |
in14.txt | AC | 21 ms | 9088 KB |
in15.txt | AC | 1 ms | 2176 KB |
in16.txt | AC | 1 ms | 2176 KB |
in17.txt | AC | 1 ms | 2176 KB |
in18.txt | AC | 1 ms | 2176 KB |
in19.txt | AC | 21 ms | 4480 KB |
in2.txt | AC | 21 ms | 4480 KB |
in20.txt | AC | 22 ms | 4480 KB |
in21.txt | AC | 22 ms | 4480 KB |
in22.txt | AC | 21 ms | 4480 KB |
in23.txt | AC | 20 ms | 4480 KB |
in24.txt | AC | 21 ms | 4480 KB |
in25.txt | AC | 1 ms | 2176 KB |
in26.txt | AC | 28 ms | 4480 KB |
in27.txt | AC | 25 ms | 4480 KB |
in28.txt | AC | 1 ms | 2176 KB |
in29.txt | AC | 18 ms | 4480 KB |
in3.txt | AC | 21 ms | 4480 KB |
in30.txt | AC | 1 ms | 2176 KB |
in31.txt | AC | 23 ms | 4480 KB |
in32.txt | AC | 22 ms | 4480 KB |
in33.txt | WA | 21 ms | 4480 KB |
in34.txt | WA | 25 ms | 4480 KB |
in35.txt | AC | 25 ms | 4480 KB |
in36.txt | AC | 25 ms | 4480 KB |
in37.txt | AC | 1 ms | 2176 KB |
in38.txt | AC | 25 ms | 4480 KB |
in39.txt | AC | 22 ms | 4480 KB |
in4.txt | WA | 23 ms | 4480 KB |
in40.txt | AC | 24 ms | 4480 KB |
in41.txt | AC | 22 ms | 4480 KB |
in42.txt | AC | 23 ms | 4480 KB |
in43.txt | AC | 24 ms | 4480 KB |
in44.txt | AC | 24 ms | 4480 KB |
in45.txt | AC | 21 ms | 4480 KB |
in5.txt | AC | 22 ms | 4480 KB |
in6.txt | AC | 20 ms | 4480 KB |
in7.txt | WA | 20 ms | 4096 KB |
in8.txt | AC | 6 ms | 2816 KB |
in9.txt | AC | 21 ms | 4480 KB |
sample1.txt | AC | 1 ms | 2176 KB |
sample2.txt | AC | 1 ms | 2176 KB |
sample3.txt | AC | 1 ms | 2176 KB |