A leap year happens every four years, so it's a year that is perfectly divisible by four. However, if the year is a multiple of 100 (1800, 1900, etc), the year must be divisible by 400.
Write a function that determines if the year is a leap year or not.
leapYear(2020) ➞ true
leapYear(2021) ➞ false
leapYear(1968) ➞ true
N/A