munchausen.nim

import math

func genCache(): array[10, int32] =
  for i in 1 .. 9:
    result[i] = int32(i ^ i)

const
  MAX = 440_000_000.int32
  cache = genCache()

func isMunchausen(number: int32): bool =
  var
    n = number
    total = 0

  while n > 0:
    let digit = n mod 10
    total += cache[digit]
    if total > number:
      return false
    n = n div 10

  total == number

proc main() =
  var output = ""
  for i in 1 ..< MAX:
    if (i > 0) and (i mod 1_000_000 == 0):
      output.add "# "
      output.addInt i
      output.add "\n"
    if isMunchausen(i):
      output.addInt i
      output.add "\n"
  echo output

when isMainModule:
  main()