/********************************************************************
  Engineering 3891 Advanced Structured Programming
  Assignment: 5  Date Due: October 20th/2000
  Name: Daryl Martin
  Student #: 9713520
  Username: darylm
*********************************************************************/

#include "assign5.h"

int size = 0;
myComplex stack[STACKSIZE];


/******************************************************************
 * push -- Put's one number on the stack.  Returns true if sucessful
 *	   and false if not
 *
 * Parameters: 
 *  myComplex x - The value to be pushed onto the stack
 *
 * Modifies: none
 *
 * Returns: True or false		Date:  10/20/00
 *******************************************************************/

bool push(myComplex x)
{
	if(size >= STACKSIZE)
	return false;
	
	stack[size++] = x;
	return true;

}

/******************************************************************
 * pop -- Pop a number from the stack and pass it back to the 
 *        referenced variable.  True if sucessful, false if not
 *
 *
 * Modifies: none
 *
 * Returns: True or false		Date:  10/20/00
 *******************************************************************/

bool pop(myComplex& x)
{
	if(size == 0)
	{
		return false;
	}	

	if(size != 0)
	{
	
		x = stack[--size];
		return true;	
	}
}

/******************************************************************
 * oper -- Carries out the operation.  ie. Multiplication, Divison
 *
 * Parameters: 
 *  char op - The operation that the want's done 
 *
 * Modifies: none
 *
 * Returns: True or false		Date:  10/20/00
 *******************************************************************/
bool oper(char op)
{
	myComplex leftSide, rightSide;
	myComplex final;

	if (size < 2 )
	return false;

	pop(rightSide);
	pop(leftSide);

	switch (op) 
	{
	
	case '+':
		final.re = (leftSide.re + rightSide.re);
		final.im = (leftSide.im + rightSide.im);
	break;

	case '-':
		final.re = (leftSide.re - rightSide.re);
		final.im = (leftSide.im - rightSide.im);
	break;

	case '*':
	final.re = (leftSide.re * rightSide.re) - (leftSide.im * rightSide.im);
	final.im = (leftSide.re * rightSide.im) + (leftSide.im * rightSide.re);
	break;

	case '/':
		if ((rightSide.re == 0) && (rightSide.im == 0))
		{
			push(leftSide);
			push(rightSide);
			return false;
  		}
	
	final.re = ((leftSide.re * rightSide.re + leftSide.im * rightSide.im)/(rightSide.re * rightSide.re + rightSide.im * rightSide.im));
	final.im = ((rightSide.re * leftSide.im - rightSide.im * leftSide.re)/(rightSide.re * rightSide.re + rightSide.im * rightSide.im));
	break;
	
	default:
		push(leftSide);
		push(rightSide);
		return false;
		break;
	}
	push(final);
	return true;
}