Mortal Fibonacci Rabbits

wabbits.nim

import strutils
import math

const 
    input = "95 17".split(" ")
    n = input[0].parseInt
    m = input[1].parseInt


proc mortalRabbits(n: int, m: int): uint64 =
    var a = newSeq[uint64](m)
    a[m-1] = 1
    for generation in 1..n-1:
        var children: uint64 = 0
        for i in 0..m-2:
            children += a[i]
        for i in 0..m-2:
            a[i] = a[i+1]
        a[m-1] = children
    result = a.sum

echo mortalRabbits(n,m) # shows 13175509047921107537
#should be 31622253121630659153