Difficulty Level: Easy

Submissions: 470 Accuracy:


[Reverse First K elements of Queue (Function Problem)]

Given an integer k and a queue of integers, we need to reverse the order of the first k elements of the queue, leaving the other elements in the same relative order.

Only following standard operations are allowed on queue.

  • enqueue(x) : Add an item x to rear of queue
  • dequeue() : Remove an item from front of queue
  • size(( : Returns number of elements in queue.
  • front() : Finds front item.


Input : Q = [10, 20, 30, 40, 50, 60, 
            70, 80, 90, 100]
        k = 5
Output : Q = [50, 40, 30, 20, 10, 60, 
             70, 80, 90, 100]

First line consists of T test cases. First line of every test case consists of 2 integers, N and K, denoting number of elements and number of elements to be reversed respectively. Second line of every test case consists of elements of array.

Single line output, print the modified queue.



5 3
1 2 3 4 5
3 2 1 4 5 

Note:The Input/Ouput 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: Saksham Raj Seth
Author: justCalvin

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