双向循环队列解析

 

  双向循环队列是在循环队列的基础之上，

public class Deque {       private int maxSize;       private int left;       private int right;       private int nItems;       private long[] myDeque;       //constructor       public Deque(int maxSize){           this.maxSize = maxSize;           this.myDeque = new long[this.maxSize];           this.nItems = 0;           this.left = this.maxSize;           this.right = -1;       }       //insert a number into left side       public void insertLeft(long n){           if(this.left==0) this.left = this.maxSize;           this.myDeque[--this.left] = n;           this.nItems++;       }       //insert a number into right side       public void insertRight(long n){           if(this.right==this.maxSize-1) this.right = -1;           this.myDeque[++this.right] = n;           this.nItems++;       }       //remove from left       public long removeLeft(){           long temp = this.myDeque[this.left++];           if(this.left==this.maxSize) this.left = 0;           this.nItems--;           return temp;       }       //remove from right       public long removeRight(){           long temp = this.myDeque[this.right--];           if(this.left==-1) this.left = this.maxSize-1;           this.nItems--;           return temp;       }       //return true if deQue is empty       public boolean isEmpty(){           return (this.nItems==0);       }       //return size of the deQue       public int size(){           return this.nItems;       }   }