Java Collection | Set 3 (HashMap) Part-2
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  Difficulty: Easy   Marks: 2

Implement different operations on Hashmap.

The first line of input contains an integer T denoting the no of test cases. Then T test cases follow. The first line of input contains an integer Q denoting the no of queries . Then in the next line are Q space separated queries .
A query can be of four types 
1. a x y (adds an entry with key x and value y to the Hashmap)
2. b x (print value of  x if present in the Hashmap else print -1. )
3. c (prints the size of the Hashmap)
4. d x (removes an entry with key x from the Hashmap)

The output for each test case will  be space separated integers denoting the results of each query . 


Example(To be used only for expected output):

a 1 2 a 66 3 b 66 d 1 c
a 1 66 b 5 c

3 1
-1 1

Explanation :
For the first test case

There are five queries. Queries are performed in this order
1. a 1 2     -->  map has a key 1 with value 2 
2. a 66 3   ---> map has a key 66 with value 3
3. b 66      ---> prints the value of key 66 if its present in the map ie 3.
4. d 1        ---> removes an entry from map with key 1
5. c           ---> prints the size of the map ie 1

For the sec test case 
There are three queries. Queries are performed in this order
1. a 1 66   ---> adds a key 1 with a value of 66 in the map
2. b 5        --->  since the key 5 is not present in the map hence -1 is printed.
3. c           ---> prints the size of the map ie 1

Note:The Input/Output format and Example given are used for system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from stdin/console. The task is to complete the function specified, and not to write the full code.

** For More Input/Output Examples Use 'Expected Output' option **

Contributor: Amit Khandelwal
Author: Amit Khandelwal 1

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