Java实现一个顺序表的完整代码

public class MyArrayList {
   
}

public int[] elem;//定义一个整形数组
    public int usize;//usize表示数组的长度
    public MyArrayList(){
        this.elem = new int[5];
}

public void display(){
        for (int i = 0; i < this.usize; i++) {
            System.out.print(this.elem[i]+" ");
        }
        System.out.println();
    }

public boolean isFull(){
        if (this.usize == this.elem.length){
            return true;
        }
        return false;
    }

public void add(int pos, int data){
        //判断顺序表是否满了
        if (isFull()){
            System.out.println("顺序表已满");
            //扩容
            this.elem = Arrays.copyOf(this.elem,2*this.usize);
        }
        //判断pos的合法性
        if (pos < 0 || pos > this.usize){
            System.out.println("pos位置不合法");
            return;
        }
        //将pos位置后的数字后移
        for (int i = this.usize-1; i >= pos; i--) {
            this.elem[i+1] = this.elem[i];
        }
        this.elem[pos] = data;
        this.usize++;
    }

public boolean contains(int key){
        for (int i = 0; i < this.usize; i++) {
            if (this.elem[i] == key){
                return true;
            }
        }
        return false;
    }

public int search(int key){
        for (int i = 0; i < this.usize; i++) {
            if (this.elem[i] == key){
                return i;
            }
        }
        return -1;
    }

public boolean isEmpty(){
        return this.usize == 0;
    }

public int getPos(int pos){
        //判断顺序表是否为空
        if (isEmpty()){
            return -1;
        }
        //判断pos 位置是否合法
        if (pos < 0 || pos >= this.usize){
            return -1;
        }
        return this.elem[pos];
    }

 public void setPos(int pos,int value){
        //判断顺序表是否为空
        if (isEmpty()){
            return;
        }
        //判断pos位置是否合法
        if (pos < 0 || pos >= this.usize){
            return;
        }
        this.elem[pos] = value;
    }

  public void remove(int key){
        int index= search(key);
        if (key == -1){
            System.out.println("关键字不存在");
            return;
        }
        for (int i = key; i < this.usize-1; i++) {
            this.elem[i] = this.elem[i+1];
        }
        this.usize--;
    }

  public int size(){
        return this.usize;
    }

public void clear(){
        this.usize = 0;
    }

public class TestDemo {
    public static void main(String[] args) {
        MyArrayList myArrayList = new MyArrayList();
        //给这个顺序表写入1,2，3,4，5
        myArrayList.add(0,1);
        myArrayList.add(1,2);
        myArrayList.add(2,3);
        myArrayList.add(3,4);
        myArrayList.add(4,5);
        //打印这个顺序表
        myArrayList.display();
        //判定5这个元素是否在该顺序表中
        System.out.println(myArrayList.contains(5));
        //查找5这个元素 返回它的位置
        System.out.println(myArrayList.search(5));
        //获取3位置的元素
        System.out.println(myArrayList.getPos(3));
        //将4位置的元素重新赋值为9
        myArrayList.setPos(4,9);
        //打印新的顺序表
        myArrayList.display();
        //删除第一次出现的元素4
        myArrayList.remove(4);
        //打印新的顺序表
        myArrayList.display();
        //获取顺序表的长度
        System.out.println(myArrayList.size());
        System.out.println("清空");
        //清空顺序表
        myArrayList.clear();
        //打印新的顺序表
        myArrayList.display();
    }
}