C++PrimerPlus的程序问题，大神来看看

[sinat_30330131]

题目：
编写一个菜单驱动程序，该程序显示一个提供4个选项的菜单---每个选项用一个字母标记。如果用户使用有效选项之外的字母进行响应，程序将提示用户输入一个有效的字母，指导用户这样做为止。然后，改程序使用一条switch语句，根据用户的选择进行一个简单操作。

程序应该是这样的：
Please enter one of the following choices:
c)carnivore p)pianist
t)tree g)game
Please enter a c,p,t, or g: q
Please enter a c,p,t, or g: t
A maple is a tree.

#include<iostream>
using namespace std;
void menu();
int main()
{
	menu();
	char ch;
	cin.get(ch);
	while (ch != EOF)
	{
		while (ch!='c' && ch!='p' && ch!='t' && ch!='g')
		{
			 cout << "Please enter a c,p,t, or g: ";
			 cin.get(ch);
		}
		switch(ch)
		{
           case 'c': cout << "A maple is a carnivore.\n";
	            break;
		   case 'p': cout << "A maple is a pianist. \n";
			    break;
		   case 't': cout << "A maple is a tree. \n";
			    break;
		   case 'g': cout << "A maple is a game. \n";
			    break;
		}
		cin.get(ch);
	}
	return 0;
}
void menu()
{
	cout << "Please enter one of the following choices: \n";
	cout << "c)carnivore\t" << "p)pianist\n";
	cout << "t)tree\t" << "g)game\n";
}

实际运行后出现如下错误，麻烦大神帮忙看一下，真看不懂。。

[赵4老师]

27行前加cin.clear();