Submission #1645783
Source Code Expand
#include<iostream> #include<vector> #include<algorithm> #include<cstring> #include<cstdio> #include<cmath> #include<cstdlib> #include<ctime> #include<queue> #include<set> #include<map> #include<stack> #include<bitset> using namespace std; typedef long long LL; const int N=2e5; int gi() { int w=0;bool q=1;char c=getchar(); while ((c<'0'||c>'9') && c!='-') c=getchar(); if (c=='-') q=0,c=getchar(); while (c>='0'&&c <= '9') w=w*10+c-'0',c=getchar(); return q? w:-w; } int a[N]; int head[N],nxt[N],to[N]; inline LL dfs(int k,int fa) { if (!nxt[head[k]]) return a[k]; LL s=a[k]<<1,t; for (int i=head[k];i;i=nxt[i]) if (to[i]!=fa) { t=dfs(to[i],k); if (t>a[k]) puts("NO"),exit(0); s-=t; } if (s<0||s>a[k]) puts("NO"),exit(0); return s; } inline bool check(int n) { int i; for (i=1;i<=n;i++) if (nxt[head[i]]) return !dfs(i,0); return a[1]==a[2]; } int main() { int n=gi(),i,a,b,tot=0; for (i=1;i<=n;i++) ::a[i]=gi(); for (i=1;i<n;i++) { a=gi(),b=gi(); to[++tot]=b,nxt[tot]=head[a],head[a]=tot; to[++tot]=a,nxt[tot]=head[b],head[b]=tot; } puts(check(n)?"YES":"NO"); return 0; }
Submission Info
Submission Time | |
---|---|
Task | C - Cleaning |
User | laofu |
Language | C++14 (GCC 5.4.1) |
Score | 700 |
Code Size | 1176 Byte |
Status | AC |
Exec Time | 23 ms |
Memory | 5248 KB |
Judge Result
Set Name | Sample | All | ||||
---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 700 / 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 | 20 ms | 2560 KB |
in10.txt | AC | 21 ms | 2560 KB |
in11.txt | AC | 23 ms | 4864 KB |
in12.txt | AC | 23 ms | 4736 KB |
in13.txt | AC | 17 ms | 5248 KB |
in14.txt | AC | 17 ms | 4864 KB |
in15.txt | AC | 1 ms | 256 KB |
in16.txt | AC | 1 ms | 256 KB |
in17.txt | AC | 1 ms | 256 KB |
in18.txt | AC | 1 ms | 256 KB |
in19.txt | AC | 20 ms | 2560 KB |
in2.txt | AC | 21 ms | 2560 KB |
in20.txt | AC | 18 ms | 2560 KB |
in21.txt | AC | 18 ms | 2560 KB |
in22.txt | AC | 17 ms | 2560 KB |
in23.txt | AC | 18 ms | 2560 KB |
in24.txt | AC | 19 ms | 2560 KB |
in25.txt | AC | 1 ms | 256 KB |
in26.txt | AC | 20 ms | 2560 KB |
in27.txt | AC | 20 ms | 2560 KB |
in28.txt | AC | 1 ms | 256 KB |
in29.txt | AC | 14 ms | 2560 KB |
in3.txt | AC | 21 ms | 2560 KB |
in30.txt | AC | 1 ms | 256 KB |
in31.txt | AC | 18 ms | 2560 KB |
in32.txt | AC | 21 ms | 2688 KB |
in33.txt | AC | 21 ms | 2560 KB |
in34.txt | AC | 22 ms | 2560 KB |
in35.txt | AC | 21 ms | 2560 KB |
in36.txt | AC | 21 ms | 2560 KB |
in37.txt | AC | 1 ms | 256 KB |
in38.txt | AC | 19 ms | 2560 KB |
in39.txt | AC | 17 ms | 2560 KB |
in4.txt | AC | 21 ms | 2560 KB |
in40.txt | AC | 20 ms | 2560 KB |
in41.txt | AC | 21 ms | 2560 KB |
in42.txt | AC | 21 ms | 2560 KB |
in43.txt | AC | 19 ms | 2560 KB |
in44.txt | AC | 21 ms | 2560 KB |
in45.txt | AC | 22 ms | 2560 KB |
in5.txt | AC | 20 ms | 2560 KB |
in6.txt | AC | 21 ms | 2560 KB |
in7.txt | AC | 18 ms | 2304 KB |
in8.txt | AC | 6 ms | 768 KB |
in9.txt | AC | 21 ms | 2560 KB |
sample1.txt | AC | 1 ms | 256 KB |
sample2.txt | AC | 1 ms | 256 KB |
sample3.txt | AC | 1 ms | 256 KB |