【数据结构+Java】Java实现简单队列、循环队列操作

Java实现简单队列、循环队列操作

1.简单队列

package queue;

import java.util.Scanner;
/**
* 队列节点
* @author wsz
* @date 2018年1月18日
*/
class Node{
String name;
int age;
}
/**
* 队列
* @author wsz
*/
class Queue{
static final int SIZE = 4;
Node[] queue = new Node[SIZE];

int head;
int tail;

Queue init() {
Queue q = new Queue();
q.head = 0;
q.tail = 0;
return q;
}

boolean isEmpty(Queue q) {
boolean temp = false;
if(q.head == q.tail)
temp = true;
return temp;
}

boolean isFull(Queue q) {
if(q.tail == SIZE)
return true;
return false;
}

void clearQueue(Queue q) {
q.head = 0;
q.tail = 0;
}

void feeeQueue(Queue q) {
q = null;
}

int insertQueue(Queue q,Node data) {
if(q.tail == SIZE) {
System.out.println(SIZE+"队列已满");
return -1;
}else {
q.queue[q.tail++] = data;
return q.tail;
}
}

Node outQueue(Queue q) {
if(q.head == q.tail) {
System.out.println("队列已空");
return null;
}else {
return q.queue[q.head++];//每次出队，头部后移
}
}

Node peekQueue(Queue q){
if(isEmpty(q)) {
System.out.println("空队列");
return null;
}else {
return q.queue[q.head];//只输出头部节点
}
}

int lenQueqe(Queue q) {
return q.tail - q.head;
}
}
public class QueueDemo {

public static void main(String[] args) {
Queue queue = new Queue();
Queue q = queue.init();

Scanner input = new Scanner(System.in);
System.out.println("入队(输入0 0 退出)");
do {
Node data = new Node();
data.name = input.next();
data.age  = input.nextInt();
if("0".equals(data.name))
break;
queue.insertQueue(q, data);
}while(true);

System.out.println("出队列：按任意非0键进行出队列操作");
String temp = input.next();
while(!"0".equals(temp)) {
Node out = queue.outQueue(q);
if(out == null)
break;
System.out.println(out.name+"_"+out.age);
temp = input.next();
}
queue.feeeQueue(q);

input.close();
}

}

2.循环队列

package queue;

import java.util.Scanner;
/**
* 队列节点
* @author wsz
* @date 2018年1月18日
*/
class Data{
String name;
int age;
}

class CycleQueue{
//实际队列可填充数据为3
static int SIZE = 4;
//模拟队列结构
Data[] data = new Data[SIZE];

int head,tail;

/**
* 初始化：头尾均为0
* @return
*/
CycleQueue init() {
CycleQueue cq = new CycleQueue();
cq.head = 0;
cq.tail = 0;
return cq;
}

/**
* 当头尾相等时为空
* @param cq
* @return
*/
boolean isEmpty(CycleQueue cq) {//相等为空
if(cq.tail == cq.head)
return true;
return false;
}

/**
* 判断是否填充满(SIZE-1)
* @param cq
* @return
*/
boolean isFull(CycleQueue cq) {
if((cq.tail+1) % SIZE == cq.head)
return true;
return false;
}

/**
* 插入数据:(tail+1)%SIZE 即实际的存储位置
* @param cq
* @param data
* @return
*/
int insertCycleQueue(CycleQueue cq,Data data) {
if(isFull(cq)) {
System.out.println("队列满");
return -1;
}else {
cq.data[ (cq.tail++) % SIZE] = data;
System.out.println("队长度:"+cq.lenCycleQueue(cq));
return cq.tail;
}
}
/**
* 出队列
* @param cq
* @return
*/
Data outCycleQueue(CycleQueue cq) {
if(isEmpty(cq)) {
System.out.println("队空");
return null;
}else {
Data d = cq.data[ (cq.head) % SIZE];
cq.data[ (cq.head) % SIZE] = null; //出队列该位置要置空
cq.head++;	//后移一位
return d;
}
}

/**
* 队列长度
* @param cq
* @return
*/
int lenCycleQueue(CycleQueue cq) {
return (cq.tail-cq.head +SIZE) % SIZE;
}

/**
* 展示全部队列数据
* @param cq
*/
void showCycleQueue(CycleQueue cq){
if(isEmpty(cq)) {
System.out.println("队空");
}else {
Data[] d = cq.data;
for(int i =0; i<d.length;i++) {
if(d[i] != null)
System.out.print(" "+i+":"+d[i].age+"_"+d[i].name);
}
System.out.println("");
}
}

}
public class CycleQueueDemo {

/**
* @param args
*/
public static void main(String[] args) {
CycleQueue cq = new CycleQueue();
CycleQueue queue = cq.init();

Scanner input = new Scanner(System.in);
do {
System.out.println("1插入队列 2数据出队 3展示队列 0退出");
int select = input.nextInt();
if(select == 1) {
insert(cq,queue,input);
}else if(select == 2) {
out(cq,queue,input);
}else if(select == 3){
show(cq,queue);
}else {
break;
}
}while(true);
input.close();
}

static void show(CycleQueue cq, CycleQueue queue) {
cq.showCycleQueue(queue);
}

static void insert(CycleQueue cq, CycleQueue queue, Scanner input) {
System.out.println("入队");
Data data = new Data();
data.name = input.next();
data.age  = input.nextInt();
cq.insertCycleQueue(queue, data);
}

static void out(CycleQueue cq, CycleQueue queue, Scanner input) {
System.out.println("即将出队");
Data out = cq.outCycleQueue(queue);
if(out != null)
System.out.println(out.age+"_"+out.name+"---剩余长度:"+cq.lenCycleQueue(queue));
}
}