Java编程题：输入手机号，输出手机号数字数组和索引数组

import java.util.Scanner;
import java.util.Arrays;

public class test{
    public static void main(String[] args){
        
        System.out.println("请输入手机号:");
        Scanner sc = new Scanner(System.in);
        
        String s = sc.nextLine();    
        
        String longStr = "";
        
        for(char ch:s.toCharArray()){
            if (Character.isDigit(ch)){
                longStr += ch;
            }
        }
        
        String shortStr = "";
        
        for(char ch:longStr.toCharArray()){
            if (shortStr.indexOf(ch) == -1){
                shortStr += ch;
            }
        }
        
        int[] arr = new int[shortStr.length()];
        
        for(int i=0;i<shortStr.length();i++){
            int one = Integer.parseInt(String.valueOf(shortStr.charAt(i)));
            arr[i] = one;
        }
        
        reverse(arr);
        
        int[] index = new int[longStr.length()];
        
        for(int i=0;i<longStr.length();i++){
            int one = Integer.parseInt(String.valueOf(longStr.charAt(i)));
            for(int j=0;j<arr.length;j++){
                if (arr[j] == one){
                    index[i] = j;
                }
            }            
        }
        
        System.out.println(Arrays.toString(arr));
        System.out.println(Arrays.toString(index));
        
        String phoneStr = "";
        
        for(int i:index){
            phoneStr += arr[i];
        }
        
        System.out.println(phoneStr);        
    }
    
    private static void reverse(int[] arr){            
        for(int i=0;i<arr.length;i++){            
            for(int j=i+1;j<arr.length;j++){                                    
                if (arr[i]<arr[j]){
                    int val = arr[i];
                    arr[i] = arr[j];
                    arr[j] = val;                    
                }
            }
        }
    }
}