C++ switch statement arrange the statements to make them more efficient

#include <iostream>
using namespace std;
int main()//from   w  w w. j av  a2 s.c o m
{
   char choice;
   do 
   {
      cout << "S - Sales \n";
      cout << "A - Accounting \n";
      cout << "E - Engineering \n";
      cout << "P - Payroll \n";
      cout << "What is your choice? ";
      cin >> choice;
      // Convert choice to uppercase (if they
      // entered lowercase) with the ASCII table.
      if ((choice>=97) && (choice<=122))
      {
         choice -= 32;
      }        // Subtract enough to make uppercase.
   } while ((choice!='S')&&(choice!='A')&& (choice!='E')&&(choice!='P'));

   switch (choice)
   {
      case ('E') : {
         cout << "\n Your meeting is at 2:30";
         break;
      }
      case ('S') : {
         cout << "\n Your meeting is at 8:30";
         break;
      }
      case ('A') :
      {
         cout << "\n Your meeting is at 10:00";
         break;
      }
      case ('P') :
      {
         cout << "\n Your meeting has been " << "canceled";
         break;
      }
   }
   return 0;
}