Submission #1694716
Source Code Expand
#include<cstdio> #include<cstring> #include<algorithm> #define N 100010 #define ll long long using namespace std; struct edge{int x, y, next;}a[N*2]; int n, w[N], x, y, l, p[N], ff, f[N], du[N], root; inline void add(int x, int y){a[++l].x=x; a[l].y=y; a[l].next=p[x]; p[x]=l;} inline void dp(int x, int fa){ if(!a[p[x]].next){f[x]=w[x]; return;} for(int i=p[x]; i; i=a[i].next)if(fa!=a[i].y)dp(a[i].y, x); if(!ff)return; int mx=0; ll sum=0, R, s; for(int i=p[x]; i; i=a[i].next)if(fa!=a[i].y){mx=max(mx, f[a[i].y]); sum+=f[a[i].y];} if(mx*2>=sum)R=sum-mx; else R=sum>>1; s=sum-w[x]; if(s<0||s>R){ff=0; return;} f[x]=sum-s*2; } int main(){ scanf("%d", &n); for(int i=1; i<=n; i++)scanf("%d", &w[i]); l=0; memset(p, 0, sizeof(p)); memset(du, 0, sizeof(du)); for(int i=1; i<=n-1; i++){scanf("%d%d", &x, &y); add(x, y); add(y, x); du[x]++; du[y]++;} if(n==2){if(w[1]==w[2])printf("YES"); else printf("NO"); return 0;} for(int i=1; i<=n; i++)if(du[i]>=2)root=i; ff=1; dp(root, 0); if(ff&&f[root])ff=0; if(ff)printf("YES"); else printf("NO"); return 0; }
Submission Info
Submission Time | |
---|---|
Task | C - Cleaning |
User | leoly |
Language | C++14 (GCC 5.4.1) |
Score | 700 |
Code Size | 1097 Byte |
Status | AC |
Exec Time | 34 ms |
Memory | 6272 KB |
Compile Error
./Main.cpp: In function ‘int main()’: ./Main.cpp:22:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ ./Main.cpp:23:43: 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("%d", &w[i]); ^ ./Main.cpp:25:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1; i<=n-1; i++){scanf("%d%d", &x, &y); add(x, y); add(y, x); du[x]++; du[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 | 33 ms | 4096 KB |
in10.txt | AC | 33 ms | 4096 KB |
in11.txt | AC | 34 ms | 5888 KB |
in12.txt | AC | 34 ms | 5760 KB |
in13.txt | AC | 30 ms | 6016 KB |
in14.txt | AC | 30 ms | 6272 KB |
in15.txt | AC | 1 ms | 896 KB |
in16.txt | AC | 1 ms | 896 KB |
in17.txt | AC | 1 ms | 896 KB |
in18.txt | AC | 1 ms | 896 KB |
in19.txt | AC | 33 ms | 4096 KB |
in2.txt | AC | 33 ms | 4096 KB |
in20.txt | AC | 33 ms | 4096 KB |
in21.txt | AC | 33 ms | 4096 KB |
in22.txt | AC | 33 ms | 4096 KB |
in23.txt | AC | 33 ms | 4096 KB |
in24.txt | AC | 33 ms | 4096 KB |
in25.txt | AC | 1 ms | 896 KB |
in26.txt | AC | 34 ms | 4096 KB |
in27.txt | AC | 34 ms | 4096 KB |
in28.txt | AC | 1 ms | 896 KB |
in29.txt | AC | 30 ms | 4096 KB |
in3.txt | AC | 34 ms | 4096 KB |
in30.txt | AC | 1 ms | 896 KB |
in31.txt | AC | 33 ms | 4096 KB |
in32.txt | AC | 33 ms | 4096 KB |
in33.txt | AC | 34 ms | 4096 KB |
in34.txt | AC | 33 ms | 4096 KB |
in35.txt | AC | 33 ms | 4096 KB |
in36.txt | AC | 33 ms | 4096 KB |
in37.txt | AC | 1 ms | 1024 KB |
in38.txt | AC | 33 ms | 4096 KB |
in39.txt | AC | 33 ms | 4096 KB |
in4.txt | AC | 34 ms | 4096 KB |
in40.txt | AC | 33 ms | 4096 KB |
in41.txt | AC | 34 ms | 4096 KB |
in42.txt | AC | 34 ms | 4096 KB |
in43.txt | AC | 34 ms | 4096 KB |
in44.txt | AC | 33 ms | 4096 KB |
in45.txt | AC | 34 ms | 4096 KB |
in5.txt | AC | 33 ms | 4096 KB |
in6.txt | AC | 34 ms | 4096 KB |
in7.txt | AC | 30 ms | 3712 KB |
in8.txt | AC | 8 ms | 1664 KB |
in9.txt | AC | 33 ms | 4096 KB |
sample1.txt | AC | 1 ms | 896 KB |
sample2.txt | AC | 1 ms | 896 KB |
sample3.txt | AC | 1 ms | 896 KB |