编辑代码

using System;  
  
class Program  
{  
    static void Main()  
    {  
        const int maxTries = 10;  
        int tries = 0;  
        bool understood = false;  
  
        while (!understood && tries < maxTries)  
        {  
            Console.Write("这道题你会做了吗? (y/n): ");  
            string answer = Console.ReadLine();  
  
            if (answer.ToLower() == "y")  
            {  
                understood = true;  
                Console.WriteLine("放学了!");  
            }  
            else if (answer.ToLower() == "n")  
            {  
                Console.WriteLine("老师再讲一遍...");  
                tries++;  
            }  
            else  
            {  
                Console.WriteLine("请输入y或n");  
            }  
        }  
  
        if (tries == maxTries)  
        {  
            Console.WriteLine("你已经听了{0}遍，但似乎还是不太明白。放学了!", maxTries);  
        }  
    }  
}