/*

Write a C program that performs the '@@' operation on a variety of
combinations of numbers input by the user.

The '@@' operation is defined as follows:

  a @@ b = (a*a + 2*b) / (3*a*b + 2*(a-b))

Have the user enter two doubles called X and Y and perform the
'@@' operation on the following combinations of X, Y, and 1:

  X @@ 1
  X @@ X
  X @@ Y
  Y @@ 1
  Y @@ Y
  Y @@ X

Remarks: Please replicate the exact text of the prompts and the
output. Make sure the results of the '@@' operation are printed with
two digits of precision (i.e., "%.2f" in printf). Even though the text
must be the same, the numbers will be different depending on the user
input.

Important Note: The '@@' operator is ficticious and is not a native
C operator. Also, it is not a valid character in the name of a
variable or function.


============= START OF SAMPLE RUN =======================
Input X:
2.5
Input Y:
2.0
The results of '@@' operation:

X @@ 1 = 0.79
X @@ X = 0.60
X @@ Y = 0.64

Y @@ 1 = 0.75
Y @@ Y = 0.67
Y @@ X = 0.64
=============  END OF SAMPLE RUN  =======================
*/

#include <stdio.h>
#include <stdlib.h>

void atOperation(double a, double b, char aChar, char bChar)
{
	double result = (a*a + 2*b) / (3*a*b + 2*(a-b));
	printf("%c @@ %c = %.2f\n", aChar, bChar, result);
}

int main(int argc, const char *argv[])
{
	double X, Y;

	printf("Input X: ");
	scanf("%lf", &X);

	printf("Input Y: ");
	scanf("%lf", &Y);

	printf("\nThe results of the '@@' operation are:\n\n");

	atOperation(X, 1, 'X', '1');
	atOperation(X, X, 'X', 'X');
	atOperation(X, Y, 'X', 'Y');

	printf("\n");

	atOperation(Y, 1, 'Y', '1');
	atOperation(Y, Y, 'Y', 'Y');
	atOperation(Y, X, 'Y', 'X');

	system("pause");
	return 0;
}