/*
 * question8a.c
 * FINAL
 * By: John Stile
 * Summery: Convert a fahrenheight to celcius
 */
#include <stdio.h>

float * f2c(float); // prototype for f2c. takes float returns pointer to a float.

int main(void)
{
  float fahr; // declare float named fahr
  float *cel; // delcare float pointer cel

  printf("This program converts fahrenheight[F] to celsius[c].\n"); // introduction

  printf("Enter a temp in fahrenheit: "); // prompt for input
  scanf("%f", &fahr); // read floating point number from stdin, 
                      // store in address of fahr
  
  cel=f2c(fahr); // call funciton f2c, passing it value stored in fahr
                 // assign return to address  stored in float pointer cel.

  printf("The %.1f F is %.1f C\n", fahr, *cel); // print contents of fahr 
                                                // and value at address pointed to by cel

  return 0; // return 0 to calling shell
}

float * f2c(float f) // header for f2c.  assigns passed value to float f
                     // funciton returns pointer to float
{
  float c; // declare float named 'c'
  float *pc; // declare float pointer named pc

  pc = &c; // assign address of variable c to pointer pc

  c = (f - 32)*5.0/9; // subtract 32 from value of f, multiply by 5.0, and divide result by 9.

  return pc; // return pointer pc to caller
}