RosettaCodeData/Task/Factorions/Nim/factorions.nim

29 lines
701 B
Nim

from math import fac
from strutils import join
iterator digits(n, base: Natural): Natural =
## Yield the digits of "n" in base "base".
var n = n
while true:
yield n mod base
n = n div base
if n == 0: break
func isFactorion(n, base: Natural): bool =
## Return true if "n" is a factorion for base "base".
var s = 0
for d in n.digits(base):
inc s, fac(d)
result = s == n
func factorions(base, limit: Natural): seq[Natural] =
## Return the list of factorions for base "base" up to "limit".
for n in 1..limit:
if n.isFactorion(base):
result.add(n)
for base in 9..12:
echo "Factorions for base ", base, ':'
echo factorions(base, 1_500_000 - 1).join(" ")