分类： Java
2021-07-12 17:21:41
import java.awt.Font;
import java.util.Scanner;
import javax.management.RuntimeErrorException;
public class CircleArrayQueueDemo {
public static void main(String[] args) {
//创建队列
CircleArrayQueue circleArrayQueue = new CircleArrayQueue(4);
char key = ' ';
Scanner scanner = new Scanner(System.in);
boolean loop = true;
while(loop) {
System.out.println("s(show):显示队列");
System.out.println("e(exit):退出程序");
System.out.println("a(add):添加数据到队列");
System.out.println("g(get):从队列取出数据");
System.out.println("h(head):查看队列头的数据");
key = scanner.next().charAt(0);
switch (key) {
case 's':
circleArrayQueue.showQueue();
break;
case 'e':
circleArrayQueue.showQueue();
break;
case 'a':
System.out.println("输入一个数");
int value = scanner.nextInt();
circleArrayQueue.addQueue(value);
break;
case 'g':
try {
int res = circleArrayQueue.getQueue();
System.out.printf("取出的数据是%d\n",res);
}catch (Exception e) {
System.out.println(e.getMessage());
}
break;
case 'h':
try {
int res = circleArrayQueue.headQueue();
System.out.printf("队列头的数据是%d\n",res);
}catch (Exception e) {
System.out.println(e.getMessage());
}
break;
default:
scanner.close();
loop = false;
break;
}
}
System.out.println("程序退出");
}
}
//队列
class CircleArrayQueue{
private int maxsize;
private int front;
private int rear;
private int[] arr;
//构造器
public CircleArrayQueue(int arrmaxsize) {
maxsize = arrmaxsize;
front = 0;
rear = 0;
arr = new int[maxsize];
}
//判满
public boolean isFull() {
return (rear+1)%maxsize == front;
}
//判空
public boolean isEmpty() {
return rear == front;
}
//入队
public void addQueue(int n) {
if(isFull()) {
System.out.println("队列已满，不能再添加！");
return;
}
//添加数据
arr[rear] = n;
//rear后移
rear = (rear + 1) % maxsize;
}
//出队
public int getQueue() {
if(isEmpty()) {
throw new RuntimeException("队列为空，不可取出元素！");
}
//取值
int value = arr[front];
//front后移
front = (front + 1)%maxsize;
return value;
}
//遍历
public void showQueue() {
if(isEmpty()) {
System.out.println("队列为空!");
return;
}
for(int i = front; i < front + size(); i++) {
System.out.printf("arr[%d]=%d\n",i % maxsize, arr[i % maxsize]);
}
}
//求队列有效数据的个数
public int size() {
return (rear + maxsize - front) % maxsize;
}
//显示队头元素
public int headQueue() {
if(isEmpty()) {
throw new RuntimeException("队列为空，不可取出元素！");
}
return arr[front];
}
}
