// Mar10.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

void print_m(void);

float get_sum(float x, float y);

float get_difference(float x, float y);

float get_product(float x, float y);

float get_quotient(float x, float y);

float get_square(float x);

float get_cube(float x);

int get_factorial(int n);


int _tmain(int argc, _TCHAR* argv[])
{
    int option, continue_key;
	float x, y;
    int n, j;
	char c, cc;

	do{
	    print_m();
		scanf("%d", &option);
		switch(option){
			case 1: printf("Enter the values of x and y, with a space between them, for sum x + y:\n ");
				    scanf("%f%f", &x, &y);
				    printf("\n\n%f + %f = %f\n\n", x, y, get_sum(x, y));
					printf("Press <Enter> to continue:\n\n");
					c = getchar();
					while( ( c = getchar() ) != '\n')
						cc = c;
				    break;
			case 2: printf("Enter the values of x and y, with a space between them, for difference x + y:\n ");
				    scanf("%f %f", &x, &y);
				    printf("\n\n%f - %f = %f\n\n", x, y, get_difference(x, y));
					printf("Press <Enter> to continue:\n\n");
					c = getchar();
					while( ( c = getchar() ) != '\n')
						cc = c;
				    break;
			case 3: printf("Enter the values of x and y, with a space between them, for product x * y:\n ");
				    scanf("%f %f", &x, &y);
				    printf("\n\n%f * %f = %f\n\n", x, y, get_product(x, y));
					printf("Press <Enter> to continue:\n\n");
					c = getchar();
					while( ( c = getchar() ) != '\n')
						cc = c;
				    break;
			case 4: printf("Enter the values of x and y, with a space between them, for quotient x / y:\n ");
				    scanf("%f %f", &x, &y);
					if (y == 0)
					{
						printf("\n\nYou fool ... you can't divide by 0.\n\n");
						for(j = 1; j<=50; j++)
							printf("\a");
					}
					else
				        printf("\n\n%f / %f = %f\n\n", x, y, get_quotient(x, y));
					printf("Press <Enter> to continue:\n\n");
					c = getchar();
					while( ( c = getchar() ) != '\n')
						cc = c;
				    break;
			case 5: printf("Enter the value of x to square:\n ");
				    scanf("%f", &x);
					printf("\n\n%f squared = %f\n\n", x, get_square(x));
					printf("Press <Enter> to continue:\n\n");
					c = getchar();
					while( ( c = getchar() ) != '\n')
						cc = c;
				    break;
			case 6: printf("Enter the value of x to cube:\n ");
				    scanf("%f", &x);
					printf("\n\n%f cubed = %f\n\n", x, get_cube(x));
					printf("Press <Enter> to continue:\n\n");
					c = getchar();
					while( ( c = getchar() ) != '\n')
						cc = c;
				    break;
			case 7: printf("Enter the value of n (must be an integer) to compute n!:\n ");
				    scanf("%d", &n);
					printf("\n\n%d ! = %d\n\n", n, get_factorial(n));
					printf("Press <Enter> to continue:\n\n");
					c = getchar();
					while( ( c = getchar() ) != '\n')
						cc = c;
				    break;
			case 0: break;
			default: break;
		}
	   } while (option != 0);
	return (0);
}


void print_m(void)
{
	int i;

    for(i=1; i<40; i++)
        printf("\n");

    printf("Menu of a lot of math functions...\n\n");
    printf("Option    Action\n");
    printf("------    ------\n");
	printf("   1      Compute Sum: x + y \n");
	printf("   2      Compute Difference: x - y \n");
	printf("   3      Compute Product: x * y \n");
	printf("   4      Compute Quotient: x / y \n");
    printf("   5      Compute x^2 \n");
    printf("   6      Compute x^3 \n");
    printf("   7      Compute n! \n");
    printf("   0      End This Program \n\n\n");
    printf("Enter option 1 ... 7, or 0 to STOP\n\n");
    return;
}


float get_sum(float x, float y)
{
	return(x + y);
}


float get_difference(float x, float y)
{
	return(x - y);
}

float get_product(float x, float y)
{
	return(x * y);
}

float get_quotient(float x, float y)
{
	return(x / y);
}


float get_square(float x)
{
	return(x*x);
}

float get_cube(float x)
{
	return(x*x*x);
}

int get_factorial(int n)
{
int i, fac = 1;

if(n == 0)
    return(1);
else if( (n > 12) || (n < 0) )
    return(-1);
else
    for(i=1; i<=n; i++)
		fac *= i;

return fac;
}