MyQueue.java

package cx.Linear;

public class MyQueue {
    int[] elements;

    public MyQueue() {
        elements = new int[0];
    }

    //入队
    public void add(int element) {
        int[] newArr = new int[elements.length + 1];
        for (int i = 0; i < elements.length; i++) {
            newArr[i] = elements[i];
        }
        newArr[elements.length] = element;
        elements = newArr;
    }

    //出队
    public int poll() {
        if (elements.length == 0) {
            throw new RuntimeException("queue is empty");
        }
        int element = elements[0];
        int[] newArr=new int[elements.length-1];
        for (int i=0;i<newArr.length;i++){
            newArr[i]=elements[i+1];
        }
        elements=newArr;
        return element;
    }

    //判断是否为空
    public boolean isEmpty(){
        return elements.length==0;
    }

}