14835 - Friendship   

Description

Write a program to determine friendship relationships.
First, we need to define what a person is. We assume there are n people, each with an integer id between 1 and n, and a name of at most 32 characters. According to the usual definition, friendship is mutual.

Suppose you have a binary file friends that contains all friendship information.
The file friends contains the following data in order:

  • The number of people n, occupying 4 bytes.

  • The contents of n structs of type person.

  • The number of friendship pairs f, occupying 4 bytes.

  • The contents of f structs of type friends.

Next, you need to read a series of commands from the keyboard.
Each command contains two names.
If the two names are friends—that is, if there exists a struct friends entry that matches the two names—output "yes"; otherwise, output "no".

The program must process all input until EOF.

Input

The two names.

Ex. John Mary
Tom Mary
Jack Tom

Output

Whether if they are friends.
Ex. yes
no
no

Sample Input  Download

Sample Output  Download




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