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();
     }
 }