// Zeinalipour-Yazti Demetrios
// csyiazti
// cs10xx -  Lab Sec#25-#29
// lab10
/* This program deals with arrays. It declares an array of 10 integers and fill
 * this array with values at compile-time. It then shifts the values in the array
 * to the right (circularly) by a user specified amount. Finally it prints 
 * the array before and after the shifting.
 */

#include <iostream>

using namespace std;

const int SIZE = 10; // the size of the array

/* Get value from user along with error checking etc
 * @return : the INT value given by the user
 */
int getUserTimes()
{
	int val;
	cout << "Please enter how many elements to shift the array: ";
	cin >> val;

	while (cin.fail())
	{
		cout << "#ERROR - Only integer  values are allowed!\n";
		cin.clear();
		cin.ignore(80, '\n');
		cout << "Please enter how many elements to shift the array: ";
		cin >> val;
	}
	return val;
}


/* Print the passed array on the screen
 * @return : void
 */
void printArray(int myarray[])
{
	cout << "Array: [";
	for (int i=0; i< SIZE; i++)
	{
		cout << myarray[i];
		if (i!=SIZE-1) 
		{ cout << ", "; }
	}
	cout << "]\n";
}

/* Shift the elements in the passed array by 1 position (circularly)
 * @return : void
 */
void shiftOne(int myarray[])
{
	int temp = myarray[SIZE-1]; // assign last element to a temp var
	int temp2;                  // another temp variable

	for (int i=0; i<SIZE; i++)
	{
		temp2 = myarray[i]; // make a copy of ith element
		myarray[i] = temp;  // assign new value to ith element
		temp = temp2;
	}
	
}

/* Shift the elements in the passed array by times positions
 * @return : void
 */
void shiftArray(int myarray[], int times)
{	
	// function declaration
	void shiftOne(int array[]);
	
	// if the times variable is TOO big this will make our program
	// an order of magnitute faster since it avoids unecessary shifts
	times =times%SIZE;

	for (int i=0; i<times; i++)
	{
		shiftOne(myarray);
	}	
}


/* 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 myarray[10] = {3, 17, 2, 9, 12, 8, 43, 100, 55, 6};
	int x; // how many elements to shift the array

	// declare functions
	int getUserTimes();
	void printArray(int array[]);
	void shiftArray(int array[], int times);

	cout << "Array Shifter  by Demetris Zeinalipour - cs10 LAB10\n\n";

	// run the program as many times as the user wants		
	do 
	{	
		// print the array (unmodified)
		printArray(myarray);

		// how many elements to shift the array
		x = getUserTimes();

		// shift the elements
		shiftArray(myarray,x);

		// print the array (modified)
		printArray(myarray);

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


}