24 lines
676 B
Ruby
24 lines
676 B
Ruby
require 'date'
|
|
# The only case where the month has 5 weekends is when the last day
|
|
# of the month falls on a Sunday and the month has 31 days.
|
|
|
|
dates = []
|
|
1900.upto(2100) do |year|
|
|
1.upto(12) do |month|
|
|
d = Date.new(year, month, -1) # -1 is last day of month
|
|
dates << d if d.sunday? && d.day == 31
|
|
end
|
|
end
|
|
|
|
puts "There are #{dates.size} months with 5 weekends from 1900 to 2100:"
|
|
puts dates.first(5).map { |d| d.strftime("%b %Y") }
|
|
puts "..."
|
|
puts dates.last(5).map { |d| d.strftime("%b %Y") }
|
|
|
|
years_with_5w = dates.map(&:year)
|
|
|
|
years = (1900..2100).to_a - years_with_5w
|
|
|
|
puts "There are #{years.size} years without months with 5 weekends:"
|
|
puts years.join(", ")
|