题解 | #字符统计#

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        while(scan.hasNext()){
            
            String str = scan.nextLine();
            int[] count = new int[500];
            char[] ch = str.toCharArray();
            int max = Integer.MIN_VALUE;
            StringBuilder strb = new StringBuilder();
            for(char c : ch){
//                 count[Integer.parseInt(String.valueOf(c))]++;
                count[(int)c]++;
            }
            for(int i = 0; i<count.length; i++){
                max = Math.max(max,count[i]);
            }
            for(int i = max; i>0; i--){
                for(int j = 0; j<count.length; j++){
                    if(count[j] == i){
//                         strb.append(String.valueOf(j).charAt(0));
                        strb.append((char)j);
                    }
                }
            }
            System.out.println(strb.toString());
            
        }
        scan.close();
    }
}