Recreating Ruby method - flatten
Ruby Flatten
array = [1, [2, 3, [4,5]]] call flatten without argument will return one-dimensional array array.flatten #=> [1, 2, 3, 4, 5], with int argument array.flatten(1) #=> [1, 2, 3, [4, 5]]
Customized Flatten
The structure of the method
def my_flatten(n = nil)
n ? multiple_flatten(self, n) : recursion_flatten(self)
end
Flattening with argument
def single_flatten(array)
results = []
array.each do |element|
if element.is_a? Array
element.each {|value| results << value}
else
results << element
end
end
results
end
def multiple_flatten(array, n)
count = 0
arr = array
while count < n do
arr = single_flatten(arr)
count += 1
end
arr
end
Flattening an Array by One Dimension
def recursion_flatten(array, results=[])
array.each do |element|
if element.is_a? Array
recursion_flatten(element, results)
else
results << element
end
end
results
end
Other Thoroughly Flatten Way
arr = [1,2,[3,[4,[5]]]]
class Array
def thoroughly_flatten
flat = []
until empty?
thing = self.pop
if thing.is_a? Array
thing.each { |i| self << i }
else
flat << thing
end
end
flat.reverse
end
end
arr.thoroughly_flatten