public class ArrList {
    public int[] arr;
    public int count;
    public ArrList() {
        this.arr = new int[5];  //初始給5個大小空間
    }
}

public boolean isFull() {
        return this.count==this.arr.length;
    }
public void tailAdd(int data) {
        //首先判斷順序表是否已滿
        if(isFull()) {
            //順序表已滿，需要擴容，這里是擴大為原來的兩倍
            this.arr= Arrays.copyOf(this.arr,2*this.arr.length);
        }
        //程序走到這，不管有沒有擴容，此時順序表都是未滿，直接添加數(shù)據(jù)
        this.arr[this.count]=data;
        this.count++;
    }

public void add(int index,int data) {
        //首先需要判斷index的值是否合法，不合法直接拋出異常
        if(index<0||index>this.count) {
            throw new ArrayIndexOutOfBoundsException("位置非法");
        }
        if(isFull()) {
            //順序表已滿，需要擴容
            this.arr= Arrays.copyOf(this.arr,2*this.arr.length);
        }
        if(index==this.count) {
            this.arr[this.count]=data;
            this.count++;
        } else {
            //中間位置添加數(shù)據(jù)需要先把從此處開始到末尾的數(shù)據(jù)都往后移動一位，從后往前移
            for (int i = this.count-1; i >=index ; i--) {  
                this.arr[i+1]=this.arr[i];
            }
            this.arr[index]=data;
            this.count++;
        }
    }

public int find (int data) {
       for (int i = 0; i < this.count; i++) {
            if(this.arr[i]==data) {
                return i;
            }
        }
        return -1;
    }

public void delData(int data) {
        int i=find(data);
        if(i!=-1) {
            for (int j = i; j <this.count-1 ; j++) {
                this.arr[j]=this.arr[j+1];
            }
            this.count--;
            this.arr[this.count]=0;
        }
    }

public void setIndex (int index,int data) {
        if(index<0||index>=this.count) {
            throw new ArrayIndexOutOfBoundsException("位置非法");
        }
        this.arr[index]=data;
    }

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