project-euler/Sidef/100 Arranged probability.sf

#!/usr/bin/ruby

# Daniel "Trizen" Șuteu
# Date: 17 February 2017
# License: GPLv3
# https://github.com/trizen

# https://projecteuler.net/problem=100

# Runtime: 0.118s

for m in (1 .. Inf) {

    var n = (-(1 - sqrt(2)) * (3 + 2*sqrt(2))**m - 2)/4

    if (n > 1e12) {
        var b = (-(sqrt(2) - 2) * (3 + 2*sqrt(2))**m + 4)/8
        say b.round(0)
        break
    }
}