// header files
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

// local constants

/*
Name: Temperature Chart
Process: Accepts up to three numbers and prints out the Fahrenheit and Celcius
         degrees between the two numbers, with an optional step as third number.
Function input/parameters: argc and argv command line parameters
Function output/parameters: NONE
Function output/returned: NONE
Device input/---: NONE
Device output/---: NONE
Dependencies: included by standard libraries
*/
int main(int argc, char *argv[])
{
    // check if proper arguments are provided
    if (argc < 3 || argc > 4)
    {
        printf("You must provide two or three integers.\n");
        return 0;
    }
    // define the start and stops, steps if applicable
    double start = atof(argv[1]);
    double stop = atof(argv[2]);
    int step = 1;
    if (argc == 4)
    {
        // define the step if provided.
        step = atoi(argv[3]);
    }
    for (start = atof(argv[1]); start <= stop; start += step)
    {
        // print out the temperature chart
        printf("%g\t%f\n", start, (start - 32) * 5 / 9);
    }
    // end program
    return 0;
}