// PROGRAM tasks
// illustrate use of subroutines

#include "TrueBASIC.h"
int main();
void initial(double *x, double *y);
void add(double x, double y, double *sum);
void multiply(double x, double y, double *product);

int main()
{
    double product, sum, x, y;

    // note how variables are passed
    initial(&x, &y);                        // initialize variables
    add(x, y, &sum);                        // add two variables
    multiply(x, y, &product);
    printf("sum = %f    product = %f\n", sum, product);

    return 0;
}                                           // end of main program

void initial(double *x, double *y)
{
    char Stmp1_[_LBUFF_];

    printf("? ");
    fgets(Stmp1_, _LBUFF_, stdin);
    sscanf(Stmp1_, "%lg", x);
    printf("? ");
    fgets(Stmp1_, _LBUFF_, stdin);
    sscanf(Stmp1_, "%lg", y);
}

void add(double x, double y, double *sum)
{
    (*sum) = x + y;
}

void multiply(double x, double y, double *product)
{
    (*product) = x*y;
}