OJ-Problems-Source/HDOJ/1567_autoAC.cpp
2016-08-14 17:42:04 +08:00

43 lines
1.1 KiB
C++

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
bool vis[2010];
int num[2010];
int main(){
int n;
int t1,t2;
bool flag;
char a[7000];
while(~scanf("%d",&n)){
memset(num,0,sizeof(num));
flag=1;
for(int i=1;i<=n-1;i++){
memset(vis,0,sizeof(vis));
for(int j=1;j<=n/2;j++){
scanf("%d-%d",&t1,&t2);
if(vis[t1]||vis[t2]){
flag=0;
}
vis[t1]=1;
vis[t2]=1;
num[t1]++;
num[t2]++;
}
}
if(flag){
for(int i=1;i<=n;i++){
if(num[i]!=n-1){
flag=0;
break;
}
}
}
if(flag)
cout<<"Yes"<<endl;
else
cout<<"No"<<endl;
}
return 0;
}