题解 | #字符串排序#

import java.util.*;

public class Main {

public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);
    while (sc.hasNext()) {
        char[] chars = sc.nextLine().toCharArray();
        List<Character> characterList = new LinkedList<>();
        for (char ch : chars) {
            if (Character.isLetter(ch)) {
                characterList.add(ch);
            }
        }
        
        characterList.sort(Comparator.comparingInt(Character::toLowerCase));
        StringBuilder sb = new StringBuilder();
        for (int i = 0, j = 0; i < chars.length; i++) {
            if (Character.isLetter(chars[i])) {
                sb.append(characterList.get(j++));
            } else {
                sb.append(chars[i]);
            }
        }
        System.out.println(sb.toString());
        
    }
}

}