Java implementation array queue, loop array queue, chained queue

/** * File name: Queuetext.java * Time: October 22, 2014 9:05:13 * Xiu Kang */package chapter3;/** * Class Name: Arrayqueue * Description: Array implementation of queue */class array queue<anytype>{private static final int default_capacity = ten; private int front;//team Head private int rear;//team tail Private in T thesize;private anytype[] theitems;public arrayqueue () {clear ();} public void Clear () {front = 0;rear = 0;thesize = 0;ensurecapacity (default_capacity);} public Boolean isEmpty () {return thesize = = 0;//or Front = = rear;} public void Enqueue (AnyType x) {theitems[rear++] = x;thesize++;} Public AnyType dequeue () {if (thesize = = 0) return Null;thesize--;return theitems[front++];} Returns the element that precedes the queue public AnyType element () {if (IsEmpty ()) return Null;return Theitems[front];} /** * Method Name: Ensurecapacity * Description: Ensure capacity */public void ensurecapacity (int newcapacity) {if (Newcapacity < thesize) return; anytype[] Old = Theitems;theitems = (anytype[]) new object[newcapacity];for (int i = 0;i < thesize;i++) Theitems[i] = old [i];}} /** * Class Name: Cirarrqueue * Description: Loop queue (because the queue implemented by the array is moved back when the pointer is deleted this causesThe previous waste, * The loop array can solve this problem, but the loop queue may make the run time doubled) */class cirarrqueue<anytype>{private static final int default_capacity = 3; private int front;//team Head private int rear;//team tail private int thesize;private anytype[] theitems;public cirarrqueue () {clear ();} public void Clear () {Theitems = (anytype[]) New Object[default_capacity];front = 0;rear = 0;thesize = 0;} public Boolean isEmpty () {return thesize = = 0;//or Front = = rear;} public boolean Enqueue (AnyType x) {if (thesize = = default_capacity) return false;theitems[rear++] = x;thesize++;if (Rear = = default_capacity)//If the tail is back to 0rear = 0;return true;} Public AnyType dequeue () {if (thesize = = 0) return null;thesize--; AnyType temp = theitems[front];if (++front = = default_capacity)//If add 1 exceeds the array then return to 0;front = 0;return temp;} Returns the element that precedes the queue public AnyType element () {if (IsEmpty ()) return Null;return Theitems[front];}} /** * Class Name: Linkedqueue * Description: Linked list implementation queue */class Linkedqueue<anytype>{private static class Node<anytype> {Node ( AnyType data, node<anytype> next) {This.datA = Data;this.next = Next;} Private AnyType data;private node<anytype> next;} Private node<anytype> front;private node<anytype> rear;public linkedqueue () {clear ();} public void Clear () {front = Null;rear = null;} public Boolean isEmpty () {return front = = null;} public void Enqueue (AnyType x) {if (front = = Null&&rear = = null) {//at the beginning rear = new node<anytype> (x,null); Front = rear;} else{node<anytype> p = new node<anytype> (x,null); rear.next = P;rear = P;;}} Public AnyType dequeue () {if (!isempty ()) {AnyType x = Front.data;front = Front.next;return x;} return null;} Public AnyType Element () {if (!isempty ()) return Front.data;return null;}} /** * Class Name: Queuetext * Description: Array and list implementation of queue and array implementation of loop queue */public class Queuetext {/** * method Name: Main * Description: Test */public static void main (St Ring[] args) {//TODO auto-generated method stub/**** array queue Test *****//*arrayqueue<integer> q = new arrayqueue< Integer> (); Q.enqueue (1); Q.enqueue (2); Q.enqueue (3); Q.enqueue (4); System.out.println (Q.element ()); while (!q.isempty ()) System.out.println (Q.dequeue ());/********* List queue test **********//*linkedqueue<integer> Q2 = new linkedqueue<integer> (); Q2.enqueue (1); Q2.enqueue (2); Q2.enqueue (3); Q2.enqueue (4); System.out.println (Q2.element ()), while (!q2.isempty ()) System.out.println (Q2.dequeue ());/*********** cyclic queue test ****** /cirarrqueue<integer> q3 = new cirarrqueue<integer> () Q3.enqueue (1); Q3.enqueue (2); Q3.enqueue (3);                               Q3.dequeue (); Q3.enqueue (4);//Set the default capacity of 3, start 3, the queue is full, and then delete the first, the queue array in the first empty out, 4 entered, but still meet the principle of FIFO, plus Size control so that it does not overwrite the back of the Q3.enqueue (5);//does not enter System.out.println (Q3.element ()); while (!q3.isempty ()) System.out.println (Q3.dequeue ());}}

Java implementation array queue, loop array queue, chained queue