写代码的时候总是各种问题，不过最后还是通过了，花了不少时间调整。 你看看我的吧 import java.util.Scanner; public class Main {     public static void main(String[] args) {         Scanner s = new Scanner(System.in);         String str = s.nextLine()+"#";         s.close();         StringBuffer sb = new StringBuffer();         for (int i = 0; i < str.length();i++) {             for (int j = i + 1; j < str.length(); j++) {                 if (str.charAt(i) != str.charAt(j)){                     if (j - i > 1) {sb.append(j - i - 1);}                     sb.append(str.charAt(i));                                                             i=j-1;                     break;                 }             }         }         System.out.println(sb);     } }