Dictionary abstract data type （ Use a queue to complete the problem . Only queue in and queue out operations can be used to access the elements in the queue ）
Set of data elements ：
A collection of records of the same type , Each record includes a keyword and its value . Keywords must be unique , however
Several keywords can be mapped to the same value . in other words , Values need not be unique .
Basic operation ：
（1）Make： Construct an empty dictionary .
（2）Size： Returns the number of records in the dictionary .
（3）IsEmpty： Returns true if the dictionary is empty , Otherwise return false .
（4）Clear： Reset the dictionary to empty .
（5）Insert： The given record is inserted into the dictionary .
（6）Remove： Records matching the given keyword are deleted , The record is returned , Otherwise, the dictionary remains unchanged .
（7）IsPresent： Returns true if there are records matching the given keyword , Otherwise return false .
（8）Find： If there are records matching the given keyword , Then the record is returned , If not , Then return to empty .