从零学数据结构算法——线性表

1.定义一个接口 IList .java

package zcf;
/**
 * 增删改查 输出 遍历
 * @author zcf
 *
 */
public interface IList {
    public void insert(int position,Object obj) throws Exception;
    public void remove(int position) throws Exception;
    public Object get(int positon) throws Exception;
    public boolean isEmpty();
    public void display();//输出所有元素
    public int lentgth();
    public void clear();
    public int indexOf(Object obj);//首次出现该元素的序号

}

2.线性表具体实现 SqList .java

package zcf;
/**
 * 数据结构 从新学习 之 
 * 
 * 线性表
 * @author zcf
 *
 */
public class SqList implements IList{

    private Object[] listElem;//存储空间
    private int curLen;//当前长度

    public SqList(int maxSize) {
        this.listElem = new Object[maxSize];
        this.curLen = 0;
    }



    @Override
    public void insert(int position, Object obj) throws Exception {
        if (position <0 || position >curLen) {
            throw new Exception("插入的数值不合法");
        }

        if (curLen == listElem.length) {
            throw new Exception("存储空间已满");
        }

        for (int j = curLen; j >position; j--) {
            listElem[j]=listElem[j-1];
        }
        listElem[position] = obj;
        curLen++;

    }

    @Override
    public void remove(int position) throws Exception{
        if (position <0 || position >curLen-1) {
            throw new Exception("删除的数值不合法");
        }

        for (int j = position; j < curLen; j++) {
            listElem[j]=listElem[j+1];
        }
        curLen--;

    }

    @Override
    public Object get(int positon) throws Exception{
        if (positon<0||positon>curLen-1) {
            throw new Exception("");
        }
        return listElem[positon];
    }

    @Override
    public boolean isEmpty() {
        // TODO Auto-generated method stub
        return curLen == 0;
    }

    @Override
    public void display() {
        System.out.print("[");
        for(int i=0;i<curLen;i++){
            if (i !=curLen-1) {
                System.out.print(listElem[i]+",");
            }else {
                System.out.print(listElem[i]);
            }
        }
        System.out.print("]");
    }

    @Override
    public int lentgth() {
        // TODO Auto-generated method stub
        return curLen;
    }

    @Override
    public void clear() {
        curLen = 0;
    }

    @Override
    public int indexOf(Object obj) {
        int i = 0;
        while ( i < curLen&&!listElem[i].equals(obj) ) {
            i++;
        }

        if (i<curLen) {
            return i;
        }

        return -1;
    }

}

3.测试
1.查找线性表中第i个元素的前驱

package zcf;

import java.util.Scanner;

public class ListTest {
    public static void main(String[] args) throws Exception {
        SqList L = new SqList(100);
        int len = 30;
        for (int i = 0; i < len; i++) {
            L.insert(i, i);
        }
        L.display();
        int i = new Scanner(System.in).nextInt();
        if (0<i&&i<=len) {
            System.out.println("前驱是 : "+L.get(i-1));
        }else {
            System.out.println("没有前驱");
        }


    }
}