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()) {
            String line = sc.nextLine();
            char[] arr = line.toCharArray();
            List<Character> list = new ArrayList<>();
            for (char c : arr) {
                if (Character.isLetter(c)) {
                    list.add(c);
                }
            }
            list.sort(new MyComparator());
            StringBuilder sb = new StringBuilder();
            for (int i = 0, j = 0; i < line.length(); i++) {
                char c = arr[i];
                if (Character.isLetter(c)) {
                    sb.append(list.get(j++));
                } else {
                    sb.append(c);
                }
            }
            System.out.println(sb);
        }
        sc.close();
    }

    private static class MyComparator implements Comparator<Character> {
        @Override
        public int compare(Character o1, Character o2) {
            return Character.toLowerCase(o1) - Character.toLowerCase(o2);
        }
    }
}