// Zeinalipour-Yazti Demetrios
// csyiazti
// cs10xx - 
// Lab Sec#24
// lab4
	/*	
	 * This program that lets the user enter a letter, then outputs the number
	 * associated with the given letter on the telephone. No number corresponds
	 * to either Q or Z. For these letters, the program prints a message indicating
	 * that they are not used on a telephone. 
	 * ABC=2, DEF=3, GHI=4, JKL=5, MNO=6, PRS=7, TUV=8, WXY=9.
	 * The program will only recognize upper case letters, for all other characters
	 * it will output that it is an invalid character. After outputting the digit
	 * (if there is one associated with the character entered), it asks the user
	 * if they desire to see the written form of the digit and print it if they desire.
     *
	 */

#include <iostream.h>

void main()
{
	char letter;				/* The letter entered by the user               */
	bool quit  = false;			/* Should the program stop executing            */
	char quitquestion;			/* Field to store users answer on quit question */
	bool correctinput = false;  /* Has the user entered a correct input         */
	int digit2use;				/* The digit that is associated with the input  */
	
	  
	/*  Getting the letter */
	while (!correctinput) //start while1
	{ 
		  cout << "\nPlease type a letter (A-P) or (R-Y) in uppercase: ";
		  cin >> letter;
		  
		  correctinput = true;

		  switch (letter)
		  { /* with gnu compiler you could use
			 *	case 'A'..'P' : break; 
			 */ 
			case 'A': 
			case 'B': 
			case 'C': digit2use=2; break;
			case 'D': 
			case 'E': 
			case 'F': digit2use=3; break;
			case 'G': 
			case 'H': 
			case 'I': digit2use=4; break; 
			case 'J': 
			case 'K': 
			case 'L': digit2use=5; break;
			case 'M': 
			case 'N': 
			case 'O': digit2use=6; break;
			case 'P': 
			case 'R': 
			case 'S': digit2use=7; break;
			case 'T': 
			case 'U': 
			case 'V': digit2use=8; break;
			case 'W': 
			case 'X': 
			case 'Y': digit2use=9; break;

			case 'Q': correctinput = false; break;				
			case 'Z': correctinput = false; break;
			
			default: correctinput = false; cout << "Error# - Please use only (A-P) or (R-Y) in uppercase!\n\n";
		  }		
		  
		  /* Displaying the associated digit (if any) */
		  if (letter=='Q' || letter=='Z')
			{  cout << " Q or Z are not used in a telephone " << endl; }			  
		  else if (correctinput)
			{  cout << endl << letter << " is associated with the digit " << digit2use << endl; }
		  
	}	//end while1
		  

	correctinput = false; /* Setting the variable to false again - reuse it*/


	/*  Asking if the user want to see digit written out */
	while (!correctinput) // start while2
	{   correctinput = true;

		  cout << "\nWould you like to see digit written out? (y/n): ";
		  cin >> quitquestion;
		  cout << endl;
		  switch (quitquestion)
		  { case 'y' : switch (digit2use)
						  { case 1 : cout << digit2use << " is written as one"   << endl; break; 
							case 2 : cout << digit2use << " is written as two"   << endl; break; 
							case 3 : cout << digit2use << " is written as three" << endl; break; 
							case 4 : cout << digit2use << " is written as four"  << endl; break; 
							case 5 : cout << digit2use << " is written as five"  << endl; break; 
							case 6 : cout << digit2use << " is written as six"   << endl; break; 
							case 7 : cout << digit2use << " is written as seven" << endl; break; 
							case 8 : cout << digit2use << " is written as eight" << endl; break; 
							case 9 : cout << digit2use << " is written as nine"  << endl; break; 
						  }		
			case 'n' : break;
			default  : correctinput = false; 
					   cout << "Error# - Please use \"y\" for yes OR \"n\" for no!\n\n";
		  }			  
	}//end while2
		  
		  
 

}