题解 | #图片整理#

import java.util.; import java.io.;

public class Main{

//图片整理
public static void main(String[] args) {
     InputStreamReader reader = new InputStreamReader(System.in);

    try( BufferedReader br = new BufferedReader(reader)){

         char[] chars = br.readLine().toCharArray();

         quickSort(chars,0,chars.length-1);
        System.out.println(String.valueOf(chars));

    }catch (IOException e){
        System.out.println(e.getMessage());
    }
}

//快速排序算法

public static void quickSort(char[] chars , int start , int end){

    if (start>= end) return;



    char tmp  = chars[start];

    int now_start = start;
    int now_end = end;


    while(now_start<now_end ){

        while(chars[now_end] >=tmp && now_end> now_start) {
            now_end--;
        }
        if (now_end>now_start)
        chars[now_start] = chars[now_end];


        while(chars[now_start] <= tmp && now_end>now_start) {
            now_start++;
        }
        if (now_end>now_start)
        chars[now_end] = chars[now_start];
    }

    chars[now_start] =tmp;


    quickSort(chars,start,now_start-1);
    quickSort(chars,now_start+1,end);
}

}