题解 | #字符串排序#

import java.util.*;
import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        String string= scanner.nextLine();
        String[] strArray=string.split("");
        Pattern pattern=Pattern.compile("[A-Za-z]");
        List<String> lists=new ArrayList<>();
        for(String s:strArray)
        {
              if(pattern.matcher(s).find())
              {
                  lists.add(s);
              }
        }
        Collections.sort(lists, new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                return o1.toLowerCase().compareTo(o2.toLowerCase());
            }
        });

        for(int i=0;i<strArray.length;i++)
        {
            if(!pattern.matcher(strArray[i]).find())
            {
                lists.add(i,strArray[i]);
            }
        }
        StringBuilder stringBuilder=new StringBuilder();
        for(String s:lists)
        {
            stringBuilder.append(s);
        }
        System.out.println(stringBuilder.toString());
    }
}