面向对象问题append去统计字符串字符个数

Question

编程填空题，中间部分是我自己写的，但是怎么都不能输出像这样：

请教会的学长

import  java.util.Scanner;

public  class  Work6  {
        public  static  void  main(String[]  args)  {
                Scanner  input  =  new  Scanner(System.in);
                String  str  =  input.nextLine();
                StringBuilder  sb  =  new  StringBuilder("");
                
                char  current  =  str.charAt(0);
                int  count  =  1;
-----------
for (int i = 0; i < str.length(); i++) {
            for (int j = 65; j < 122; j++) {
                current=str.charAt(i);
                if (current==j){
                   count++;
                }
            }
        }

        count -= 1;

----------
                if  (count  ==  1)  sb.append(current);
                else  sb.append(current).append(count);
                
                System.out.println(sb.toString());
        }
}

```朋友们帮助一下

Answer 1

aaaabbbccddddaaaccc
这种是写成a4b3c2d4a3c3还是写成a7b3c5d4?这两种的写法不一样