题解 | #字符串排序#

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        char[] chars = in.nextLine().toCharArray();
        char[] res = new char[chars.length];
        LinkedList<Character> list = new LinkedList<>();

        for(int i = 0; i < chars.length; i++){
            if(!Character.isLetter(chars[i])){
                res[i] = chars[i];
            }
            else{
                list.add(chars[i]);
            }
        }

        list.sort(new Comparator<Character>(){
            public int compare(Character c1, Character c2){
                return Character.toLowerCase(c1) - Character.toLowerCase(c2);
            }
        });

        for(int i = 0; i < res.length; i++){
            if(res[i] == 0){
                res[i] = list.pop();
            }
        }

        System.out.println(new String(res));
    }
}