数据结构与算法~数据结构之队列和环形队列

数组模拟队列编写一个ArrayQueue类实现队列和环形队列

其中环形队列的增加是一个难点，注意新增了一个count计数的变量

public class test {
    public static void main(String[] args){
//        ArrayQueue arrayQueue=new ArrayQueue(5);
//        arrayQueue.addArrayQueue( 1 );
//        arrayQueue.addArrayQueue( 2 );
//        arrayQueue.addArrayQueue( 3 );
//        arrayQueue.showQueue();
//        System.out.println( arrayQueue.getQueue() );
//        arrayQueue.showQueue();
//        arrayQueue.headQueue();
        
        
        RingQueue ringQueue=new RingQueue(5);
        ringQueue.addArrayQueue( 1 );
        ringQueue.addArrayQueue( 2 );
        ringQueue.addArrayQueue( 3 );

        System.out.println( ringQueue.getQueue() );
        ringQueue.showQueue();
        ringQueue.addArrayQueue( 2 );
        ringQueue.addArrayQueue( 3 );
        ringQueue.addArrayQueue( 2 );
        ringQueue.showQueue();
        ringQueue.headQueue();
    }
}
class ArrayQueue{
    private int maxSize;    //最大容量
    private int front;      //头
    private int rear;       //尾
    private int[] arr;      //数组

    //创建队列的构造器
    public ArrayQueue(int size){
        maxSize=size;
        front=-1;
        rear=-1;
        arr=new int[maxSize];
    }
    public boolean isFull(){
        return rear==maxSize-1;
    }
    public boolean isEmpty(){
        return rear==front;
    }
    public void addArrayQueue(int num){         //入队
        if(isFull()){
            throw new RuntimeException("队列已满，无法加入数据");
        }else{
            rear++;
            arr[rear]=num;
        }
    }
    public int getQueue(){     //出队
        if(isEmpty()){
            throw new RuntimeException("队列为空，无法输出数据");
        }else{
            front++;
            return arr[front];
        }
    }
    public void showQueue(){
        System.out.print("当前队列内容为：");
        for(int i=front+1;i<=rear;i++){
            System.out.print(arr[i]+"  ");
        }
        System.out.println(  );
    }
    public void headQueue(){
        System.out.println("队列头为："+arr[front+1]);
    }
}
//环形队列
class RingQueue{
    private int maxSize;    //最大容量
    private int front;      //头
    private int rear;       //尾
    private int[] arr;      //数组
    private int count;

    //创建队列的构造器
    public RingQueue(int size){
        maxSize=size;
        front=-1;
        rear=-1;
        count=0;
        arr=new int[maxSize];
    }
    public boolean isFull(){
        return rear-front==maxSize;
    }
    public boolean isEmpty(){
        return rear==front;
    }
    public void addArrayQueue(int num){         //入队
        if(isFull()){
            throw new RuntimeException("队列已满，无法加入数据");
        }else{
            rear++;
            arr[(rear-front+count-1)%maxSize]=num;
        }
    }
    public int getQueue(){     //出队
        if(isEmpty()){
            throw new RuntimeException("队列为空，无法输出数据");
        }else{
            front++;
            count++;
            return arr[front%maxSize];
        }
    }
    public void showQueue(){
        if(isEmpty()){
            throw new RuntimeException("队列为空，无法输出数据");
        }else {
            System.out.print("当前队列内容为：");
            for(int i=front+1;i<=rear;i++){
                System.out.print(arr[i%maxSize]+"  ");
            }
            System.out.println(  );
        }
    }
    public void headQueue(){
        if(isEmpty()){
            throw new RuntimeException( "队列为空" );
        }
        System.out.println("队列头为："+arr[(front%maxSize)]);
    }
}