1 #include<iostream>
2 #include<
set>
3 #include<algorithm>
4 #include<
string>
5 using namespace std;
6 int main()
7 {
//freopen("C:\\Users\\Sky\\Desktop\\1.in","r",stdin);
8 int n,i;
9 string s1,s2;
10 set<
string>
a,b;
11 set<
string>
::iterator it;
12 while(cin>>
n,n)
13 {
14 for(i=
1;i<=n;i++
)
15 {
16 cin>>s1>>
s2;
17 a.insert(s1);
18 b.insert(s2);
19 }
20 for(it=b.begin();it!=b.end();it++
)
21 {
22 if(find(a.begin(),a.end(),*it)!=
a.end())
23 a.erase(*find(a.begin(),a.end(),*
it));
24 }
25
26 if(a.size()==
1)
27 cout<<
"Yes"<<
endl;
28 else
29 cout<<
"No"<<
endl;
30
31 /*
32 for(it=a.begin();it!=a.end();it++)
33 cout<<*it<<endl;*/
34 a.clear();
//清空容器
35 b.clear();
36 }
37 return 0;
38 }
View Code
转载于:https://www.cnblogs.com/Skyxj/p/3193547.html
