Java数据结构顺序表的详细讲解

public class ArrList {
    public int[] arr;
    public int count;
    public ArrList() {
        this.arr = new int[5];  //初始给5个大小空间
    }
}

public boolean isFull() {
        return this.count==this.arr.length;
    }
public void tailAdd(int data) {
        //首先判断顺序表是否已满
        if(isFull()) {
            //顺序表已满，需要扩容，这里是扩大为原来的两倍
            this.arr= Arrays.copyOf(this.arr,2*this.arr.length);
        }
        //程序走到这，不管有没有扩容，此时顺序表都是未满，直接添加数据
        this.arr[this.count]=data;
        this.count++;
    }

public void add(int index,int data) {
        //首先需要判断index的值是否合法，不合法直接抛出异常
        if(index<0||index>this.count) {
            throw new ArrayIndexOutOfBoundsException("位置非法");
        }
        if(isFull()) {
            //顺序表已满，需要扩容
            this.arr= Arrays.copyOf(this.arr,2*this.arr.length);
        }
        if(index==this.count) {
            this.arr[this.count]=data;
            this.count++;
        } else {
            //中间位置添加数据需要先把从此处开始到末尾的数据都往后移动一位，从后往前移
            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; 
    }