字符串归一化

import java.util.*;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        int[] v = new int[26];
        for(int i = 0; i < s.length(); ++i) v[s.charAt(i) - 'a']++;//统计字母个数
        for(int i = 0; i < 26; ++i){
            if(v[i] != 0){
                char temp = (char)('a' + i);
                System.out.print(temp);
                if(v[i] != 1)System.out.print(v[i]);
            }
        }
    }
}