Do exercise 3 again, but this time handle the error inside ctok().

Dara from Exercise 3

Absolute zero is the lowest temperature that can be reached; it is –273.15°C, or 0K. The above program, even when corrected, will produce erroneous results when given a temperature below this. Place a check in the main program that will produce an error if a temperature is given below –273.15°C.