Write a function which calculates leap years. The function prototype is as follows:
bool leap_year(int year);
Write the function body which returns true if the year is a leap year and false if the year is not a leap year.
NOTE: A leap year is defined as any year divisible by 4 with the following exception:
Years that are evenly divisible by 100 are not leap years, unless they are also evenly divisible by 400
Also note that any year prior to 1582 is not a leap year.
Your submission should include a fully functional program including a main program that tests your leap_year function.