Chapter 5, Problem 3C

Basic operation in double ended queue:

• The double ended queue is a queue that allows insertion and deletion at both its ends.
• The basic operations in double ended queue are following,
  • insetFront(): Adds an item at the front of Deque.
  • insertRear(): Adds an item at the rear of Deque.
  • deleteFront(): Deletes an item from front of Deque.
  • deleteRear(): Deletes an item from rear of Deque.

Pseudo code for insertion at front:

//check the queue is full or not

1. 1) First check if queue is not already full

//if the conditionis true

2) IF Front == 0 || initial position, then move Front

        to point last index of array

        //means decreasing size by 1

        front = size – 1

//if the condition is false

    Else decremented front by '1' and push

        //Set Arr[Front] as key

        current key into Arr[ Front] = key

        so the Rear remain same.

Explanation:

The above pseudo code is used to insert the element at the front of a double ended queue. In the code,

• Check that the queue is already full or not.
• If the value of “Front” is zero or it is an initial position, move the “Front”.
  • Decrement the value of “size” by 1 and set this value to “Front”.
• If the value of “Front” is not equal to zero,
  • Set the value of “Arr[]” as “key”.

Pseudo code for insertion at rear:

//check the queue is full or not

1) First check if queue is not already full

//if the value of rear is size-1

2) IF Rear == Size-1

        //set the value of Rear

        then set Rear = 0 ;

//if the value of rear is not size-1 increment Rear

Else increase Rear by '1'

        //Set Arr[Front] as key

        and add current key into Arr[ rear ] = key

        Front remain same.

Explanation:

The above pseudo code is used to insert the element at the rear of a double ended queue. In the code,

• Check that the queue is already full or not.
• If the value of “Rear” is “size-1”.
  • Set “Rear” as “0”.
• If the value of “Rear” is not equal to “size-1”, increment “Rear” by 1...