RosettaCodeData/Task/Executable-library/Nim/executable-library-1.nim

21 lines
494 B
Nim

proc hailstone*(n: int): auto =
result = @[n]
var n = n
while n > 1:
if (n and 1) == 1:
n = 3 * n + 1
else:
n = n div 2
result.add n
when isMainModule:
let h = hailstone 27
assert h.len == 112 and h[0..3] == @[27,82,41,124] and h[h.high-3..h.high] == @[8,4,2,1]
var m, mi = 0
for i in 1 ..< 100_000:
let n = hailstone(i).len
if n > m:
m = n
mi = i
echo "Maximum length ", m, " was found for hailstone(", mi, ") for numbers <100,000"