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 s = scanner.nextLine();
        System.out.println(strSort(s));
    }

    public static String strSort(String str){
        StringBuilder result = new StringBuilder();
        if(str==null || str.length()<=1){
            return str;
        }
        String temp = str.replaceAll("[^a-zA-Z]", "");
        String sortStr = sort(temp);
        int j = 0;
        for(int i = 0 ;i<str.length();i++){
            if(Pattern.matches("[a-zA-Z]",str.charAt(i)+"")){
                result.append(sortStr.charAt(j));
                j++;
            }else{
                result.append(str.charAt(i));
            }
        }
        return result.toString();
    }

    public static String sort(String str){
        if(str==null || str.length()<=1){
            return str;
        }
        char[] chars = str.toCharArray();
        for (int i = 1; i < chars.length; i++) {
            for (int j = i; j > 0; j--) {
                if(Character.toUpperCase(chars[j-1])>Character.toUpperCase(chars[j])){
                    swap(chars,j-1,j);
                }
            }
        }
        return new String(chars);
    }

    public static void swap(char[] c,int s,int e){
        char temp = c[s];
        c[s] = c[e];
        c[e] = temp;
    }
}