// Zeinalipour-Yazti Demetrios
// csyiazti
// cs10xx -  Lab Sec#25-#29
// lab6
/*		
 * This program randomly picks a number between 2 and 8 then asks the user
 * to enter a word that contains that many characters. 
 * It then checks to see if the word entered does indeed have the correct
 * number of characters and output whether they entered a good word or not.
 * The programs allows  the user to continue as many times as he wants each
 * time using a different random number.
 */

#include <iostream>
#include <cmath>
#include <ctime>
#include <string>

using namespace std;

/* This function returns us a random number in range (from,to)
 * @return : the random number
 */
int getRand(int from, int to)
{
    /* e.g (2,4) ==> range=3 [3 numbers] */
	int range = to-from+1;	
	
	// produce random number 0 <= random <= range
	int random = (rand() % range);  
	
	// return random number + from in order to scale it up to the range.
	return ( random + from );
}


/* This function asks the user to select the char "y" or "n" 
 * @return : y for yes
 *           n for no
 */
char doAgain()
{    /* defining local scope variables*/
     char value;

     cout << "\nDo you want to run the program again (y/n) ?:  ";
     cin >> value;
     while (cin.fail() || !(value=='y' || value=='n'))
	 {
		 cout << "#Error - only (y/n) are accepted!\n";
		 cin.clear();
		 cin.ignore(80, '\n');
		 cout << "Do you want to run the program again (y/n) ? :  ";
		 cin >> value;
	 }
	 cout << endl;
     return value;
}


void main()
{
	/* define variables */
	int random;     /* a random number                  */
	string word;			/* defines the type : (1=odd or 2=even) */

	/* define functions & procedures*/
	char doAgain(); /* returns 'y' or 'n' to the question whether to continue  */
	int getRand(int from, int to); // produce number : from <= random <= to
	
	/* 	srand -> randomize withou the need for entering a seed each time.
	 * This causes the computer to read its clock to obtain the value for
	 * the seed automatically.
	 * time(0) ==> returns current system time  
	 */					
	srand((unsigned)time(0)); 

	// run the program as many times as the user wants
		
	do 
	{	
		// generate random number 2<=random<=8
		random = getRand(2,8);			

		cout << "Please enter a word "<< random << " characters long: ";
		cin >> word;
		if (word.length()!=random)
			{ cout << "#Error : The given word should be " << random 
				   << " chars" << endl;
			}
		else
		{ cout << "Congratualtions! - You entered the right number of chars.\n"; } 

	} while (doAgain()=='y');

}