（1）实现一个简单的菜单程序，运行时显示"Menu: A(d

#include <iostream.h>
#include <stdlib.h>
  
void main() 
{ 
char choice,c; 
while(1) 
{ 
cout << "Menu: A(dd) D(elete) S(ort)
Q(uit)， Select one:"; 
cin >> c; 
choice = toupper(c);
if (choice == 'A')
{ 
cout << "数据已经增加. "
<< endl; 
continue; 
} 
else if (choice == 'D') 
{ 
cout << "数据已经删除. "
<< endl; 
continue; 
} 
else if (choice == 'S') 
{ 
cout << "数据已经排序. "
<< endl; 
continue; 
} 
else if (choice == 'Q') 
break; 
} 
} 
  

#include <iostream.h>
#include <stdlib.h>
  
void main() 
{ 
char choice;
while(1)
{ 
cout << "Menu: A(dd) D(elete) S(ort)
Q(uit)， Select one:";  
cin >> choice; 
switch(toupper(choice)) 
{ 
case 'A': 
cout << "数据已经增加. "
<< endl;  
break; 
case 'D': 
cout << "数据已经删除. "
<< endl;  
break; 
case 'S': 
cout << "数据已经排序. "
<< endl;  
break; 
case 'Q':
exit(0);
break;
default:
; 
} 
} 
}