题解 | #字符串排序#

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNext()){
            String str = scanner.nextLine();
            List<Character> charList = new ArrayList<>();
            for(char item:str.toCharArray()){
                if(Character.isLetter(item))
                     charList.add(item);
            }
            //Comparator比较器实现
            charList.sort(new Comparator<Character>(){
                public int compare(Character o1,Character o2){
                    return Character.toLowerCase(o1) - Character.toLowerCase(o2);
                }
            });
            StringBuilder result = new StringBuilder();
            for (int i = 0, j = 0; i < str.length(); i++) {
                if (Character.isLetter(str.charAt(i))) {
                    result.append(charList.get(j++));
                }
                else {
                    result.append(str.charAt(i));
                }
            }
            System.out.println(result);
        }
    }
}