实现顺序表2021.9.20

package linerList;

public interface ListInterface<T> {
    void Init(int initialSize);//初始化线性表

    int length();

    boolean isEmpty();//是否为空

    int ElemIndex(T t);//找到编号

    T getElem(int index) throws Exception;

    void add(int index, T t) throws Exception;//根据索引插入

    void add(T t) throws Exception;//在尾部插入

    void delete(int index) throws Exception;

    void set(int index, T t) throws Exception;

    String toString();

}

package linerList;


import com.sun.org.apache.xml.internal.security.Init;

import java.util.Arrays;

public class seqList<T> implements ListInterface<T> {
    //接口编程yyds
    //定义初试变量，链表的底层是一个数组

    private Object[] date;
    private int length;

    public seqList() {
        Init(10);
    }

    @Override
    public void Init(int initialSize) {
        this.date = new Object[initialSize];
        this.length = 0;
    }

    @Override
    public int length() {
        return this.length;
    }

    @Override
    public boolean isEmpty() {
        if (this.length == 0) {
            return true;
        }
        return false;
    }

    @Override
    public int ElemIndex(T t) {
        int len = date.length;
        for (int i = 0; i < len; i++) {
            if (date[i].equals(t)) {
                return i;
            }
        }
        return -1;
    }

    @Override
    public T getElem(int index) throws Exception {
        //首选判断数组是否越界
        if (index < 0 || index > length) {
            throw new Exception("数值越界异常");
        }

        return (T) date[index];//向下转型
    }

    @Override
    public void add(int index, T t) throws Exception {
        if (index < 0 || index > length) {
            throw new Exception("数值越界异常");
        }
        //如果内存不够用的话就扩容两倍
        if (length == date.length) {//实际的长度灯油当数组的长度
            Object[] newDate = new Object[length * 2];
            for (int i = 0; i < length; i++) {//将数据移出去
                newDate[i] = date[i];
            }
            //重新指向
            date = newDate;
        }
        //已经扩好容量，下面进行添加元素，首先要进行从索引位置向后移动
        for (int i = length - 1; i >= index; i--) {
            date[i + 1] = date[i];//将后面一个元素的数据向后移动
        }
        date[index] = t;
        length++;//顺序表长度加一
    }

    @Override
    public void add(T t) throws Exception {
        add(length,t);
    }

    @Override
    public void delete(int index) throws Exception {
        if (index < 0 || index > length) {
            throw new Exception("数值越界异常");
        }
        for (int i = index; i < length; i++) {
            date[index] = date[index + 1];
        }
        length--;//删除的时候数值减一
    }

    @Override
    public void set(int index, T t) throws Exception {
        if (index < 0 || index > length) {
            throw new Exception("数值越界异常");
        }
        date[index] = t;
        //设置某个具体的值的时候不能改变数据的长度。
    }
    //添加构造器


    @Override
    public String toString() {
        String vaString = "";
        for (int i = 0; i < length; i++) {
          vaString +=  date[i].toString() + "";
        }
        return vaString;
    }
}