Description:

A variation of determining leap years, assuming only integers are used and years can be negative and positive.

Write a function which will return the days in the year and the year entered in a string. For example, 2000, entered as an integer, will return as a string 2000 has 366 days

There are a few assumptions we will accept the year 0, even though there is no year 0 in the Gregorian Calendar.

Also, the basic rule for validating a leap year are as follows

Most years that can be divided evenly by 4 are leap years.

Exception: Century years are NOT leap years UNLESS they can be evenly divided by 400.

So the years 0, -64 and 2016 will return 366 days. Whilst 1974, -10 and 666 will return 365 days.

Test Case:

Test.describe("Basic tests") do
Test.assert_equals(year_days(0), '0 has 366 days')
Test.assert_equals(year_days(-64), '-64 has 366 days')
Test.assert_equals(year_days(2016), '2016 has 366 days')
Test.assert_equals(year_days(1974), '1974 has 365 days')
Test.assert_equals(year_days(-10), '-10 has 365 days')
Test.assert_equals(year_days(666), '666 has 365 days')
Test.assert_equals(year_days(1857), '1857 has 365 days')
Test.assert_equals(year_days(2000), '2000 has 366 days')
Test.assert_equals(year_days(-300), '-300 has 365 days')
Test.assert_equals(year_days(-1), '-1 has 365 days')
end

Solution :

def year_days(year)
  if year % 4 == 0
    if year % 100 == 0 && year % 400 != 0
      num_of_days = 365
    else
      num_of_days = 366
    end
  else
    num_of_days = 365
  end
  "#{year} has #{num_of_days} days"
end

It gets better with a single line solution

def year_days(year)
  Date.leap?(year) ? "#{year} has 366 days" : "#{year} has 365 days"   
end