18 lines
482 B
Crystal
18 lines
482 B
Crystal
def hailstone(n)
|
|
seq = [n]
|
|
until n == 1
|
|
n = n.even? ? n // 2 : n * 3 + 1
|
|
seq << n
|
|
end
|
|
seq
|
|
end
|
|
|
|
max_len = (1...100_000).max_by{|n| hailstone(n).size }
|
|
max = hailstone(max_len)
|
|
puts ([max_len, max.size, max.max, max.first(4), max.last(4)])
|
|
# => [77031, 351, 21933016, [77031, 231094, 115547, 346642], [8, 4, 2, 1]]
|
|
|
|
twenty_seven = hailstone(27)
|
|
puts ([twenty_seven.size, twenty_seven.first(4), max.last(4)])
|
|
# => [112, [27, 82, 41, 124], [8, 4, 2, 1]]
|