Class MyCircularDeque

Java/design-circular-deque.java:5–148

public class MyCircularDeque {


      int size;							//			keeping the count of elements in your array
      int front = -1;						//			keeping the index of front 
      int rear = -1;						//			keeping the index of rear
      int capacity;						//			total capacity of our DS
      int arr[];							//			array to store the elements


      /** Initialize your data structure here. Set the size of the deque to be k. */
      public MyCircularDeque(int k) {				//		initialising capacity as k
        this.size = 0 ;							//		and initialising the array
        this.capacity = k;
        arr = new int[k];
      }

      /** Adds an item at the front of Deque. Return true if the operation is successful. */
      public boolean insertFront(int value) {
        if( (this.size == this.capacity))		//  means queue is full
          return false;

        if(front == -1) {						//			 means queue is empty
          arr[0] = value;
          front = 0;
          rear = 0;
          this.size ++;						//		increase the size and return true
          return  true;
        }

        if(front == 0) {						//   if front is at 0, then add at last and make front as last
          arr[this.capacity - 1] = value;
          front = this.capacity -  1;	
        }else{									//	 else add to the left of front and make front as front - 1;
          arr[front - 1] = value;
          front --;
        }	
        this.size ++;							//	increase the size and return true..
        return true;
      }

      /** Adds an item at the rear of Deque. Return true if the operation is successful. */
      public boolean insertLast(int value) {

        if(this.size == this.capacity) 			//			means queue is full
          return false;

          if(rear == -1) {						//		means queue is empty
            arr[0] = value;						//		add the first element and return true
            front = 0;
            rear = 0;
            this.size ++;
            return true;
          }

          if(rear == this.capacity - 1) {			//		if rear is at last, means we will have to add this element at first
            arr[0] = value;						//		position and make rear as first
            rear = 0;