Java 平时作业三

自定义一个可以存储 int 类型的集合类（例如：SequenceList），封装一维数组存储数据，该 集合类具有以下方法：

（1）新增元素；

（2）在指定位置插入一个元素；

（3）按位置删除元素；

（4）按值删除元素

（5）排序（增序，降序）

（6）查询指定元素，返回下标位置。

import java.util.Scanner;

public class SequenceList {

    public static void main(String[] args) {
        int a[] = { 1,5,4,6,8,3,4,0 };
        int key;
        int elem,index;
        String c;
        boolean flag=true;
        Scanner sc = new Scanner(System.in);
        IntUtil test = new IntUtil(a);
       
      out:  while(flag) {    
             System.out.println("请输入相关选项：");
             System.out.println("（1）新增元素");
             System.out.println("（2）在指定位置插入一个元素");
             System.out.println("（3）按位置删除元素；");
             System.out.println("（4）按值删除元素 ");
             System.out.println("（5）排序（增序)");
             System.out.println("（6）排序（降序)");
             System.out.println("（7）查询指定元素，返回下标位置");
             System.out.println("（0）退出");
             key = sc.nextInt(); 
            switch(key) {
        case 1:
            System.out.println("请输入要添加的元素");
            elem=sc.nextInt();
            test.addElement(elem);
            break;
        case 2:
            System.out.println("请输入添加的元素及位置");
            elem=sc.nextInt();
            index=sc.nextInt();
            test.addElementAtIndexOf(elem, index);
            break;
        case 3:
            System.out.println("请输入要删除元素的位置");
            index=sc.nextInt();
            test.deleteElementAtIndexOf(index);
            break;
        case 4:
            System.out.println("请输入要删除的元素的值");
            elem=sc.nextInt();
            test.deleteElement(elem);
            break;
        case 5:
            test.arraySortUp();
            break;
        case 6:
            test.arraySortDown();
            break;
        case 7:
            System.out.println("请输入要查找的元素");
            elem=sc.nextInt();
            test.searchElement(elem);
            break;
        case 0:
            flag=false;
            System.out.println("程序已结束");
            break out;
        default:
            System.out.println("没有该选项，请重新输入");
            continue;
        }
        System.out.println("是否继续？y/n");
            c=sc.next();
            if(c.equals("n"))
            {    flag=false;
                System.out.println("程序已结束");
            }
            if(c.equals("y"))
                flag=true;
        }
        
    }

}


class IntUtil {
    int array[];

    public IntUtil(int a[]) {
        super();
        array = a;
    }

    public void arraySortDown() {
        // TODO Auto-generated method stub

        for (int i = 0; i < array.length; i++) {
            for (int j = i + 1; j < array.length; j++) {
                if (array[i] < array[j]) {
                    int temp = array[i];
                    array[i] = array[j];
                    array[j] = temp;
                }
            }
        }
        show();
    }

    public void arraySortUp() {
        // TODO Auto-generated method stub
        for (int i = 0; i < array.length; i++) {
            for (int j = i + 1; j < array.length; j++) {
                if (array[i] > array[j]) {
                    int temp = array[i];
                    array[i] = array[j];
                    array[j] = temp;
                }
            }
        }
        show();
    }

    void addElement(int a) {
        int[] newArray = new int[array.length + 1];

        for (int i = 0; i < array.length; i++) {
            newArray[i] = array[i];
        }

        newArray[array.length] = a;

        array = newArray;

        show();
    }

    void addElementAtIndexOf(int a, int index) {
        index=index-1;
        int[] newArray = new int[array.length + 1];

        for (int i = 0; i < index; i++) {
            newArray[i] = array[i];
        }

        newArray[index] = a;

        for (int i = index + 1; i < array.length; i++) {
            newArray[i] = array[i - 1];
        }
        newArray[array.length] = array[array.length - 1];
        array = newArray;
        show();
    }

    void deleteElementAtIndexOf(int index) {
        int[] newArray = new int[array.length - 1];

        for (int i = 0; i < index - 1; i++) {
            newArray[i] = array[i];
        }

        for (int i = index; i < array.length; i++) {
            newArray[i - 1] = array[i];
        }
        array = newArray;
        show();
    }

    void deleteElement(int a) {
        for (int i = 0; i < array.length; i++) {
            if (a == array[i]) {
                deleteElementAtIndexOf(i + 1);
            }
        }

    }

    int elementAt(int a) {
        return 0;
    }

    int searchElement(int a) {
        for(int i=0;i<array.length;i++)
        {
            if(array[i]==a)
            {    System.out.println("该数的下标为"+i);
                return 0;
            }
            
        }
        System.out.print("该数不存在");
        return 0;
    }
    
    void show() {
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i]+" ");
        }
      System.out.println();
    }
}