数据结构与算法-环形队列

package queue;

import java.util.Scanner;


public class CircleQueueTest {

    public static void main(String[] args) {
        System.out.println("请输入环形队列的大小：");
        Scanner sc = new Scanner(System.in);
        int size = sc.nextInt();
        CircleQueue queue = new CircleQueue(size + 1);
        boolean isContinue = true;
        while (isContinue) {
            System.out.println("查看队列(show)：s");
            System.out.println("添加队列(add)：a");
            System.out.println("d出队列(pop)：p");
            System.out.println("退出(exit)：e");
            String s = sc.next();
            switch (s) {
                case "s":
                    queue.showQueue();
                    break;
                case "a":
                    if (queue.isFull()) {
                        System.out.println("队列已经满了~");
                        break;
                    }
                    System.out.println("请输入数据：");
                    int number = sc.nextInt();
                    queue.addQueue(number);
                    break;
                case "p":
                    int result = queue.popQueue();
                    System.out.println("获取到队列元素：" + result);
                    break;
                case "e":
                    isContinue = false;
                    break;
                default:
                    break;
            }
        }
    }

    static class CircleQueue {
        
        private int front;
        
        private int tail;

        
        private final int maxSize;

        
        private final int[] queueData;

        
        private CircleQueue(int maxSize) {
            this.maxSize = maxSize;
            queueData = new int[maxSize];
        }

        
        public boolean isFull() {
            return (tail + 1) % maxSize == front;
        }

        
        public boolean isEmpty() {
            return tail == front;
        }

        
        public void addQueue(int number) {
            if (isFull()) {
                System.out.println("队列已经满了~");
                return;
            }
            queueData[tail] = number;
            tail = (tail + 1) % maxSize;
        }

        
        public int popQueue() {
            if (isEmpty()) {
                System.out.println("队列为空~");
                return 0;
            }
            int fontValue = queueData[front];
            front = (front + 1) % maxSize;
            return fontValue;
        }

        
        public int size() {
            return (tail - front + maxSize) % maxSize;
        }

        
        public void showQueue() {
            if (isEmpty()) {
                System.out.println("队列为空~");
                return;
            }
            for (int i = front; i < front + size(); i++) {
                System.out.println("queueData[" + i % maxSize + "]=" + queueData[i % maxSize]);
            }
        }
    }
}