Contents

module AcLibraryRb
  def floor_sum(n, m, a, b)
    res = 0

    if a >= m
      res += (n - 1) * n * (a / m) / 2
      a %= m
    end

    if b >= m
      res += n * (b / m)
      b %= m
    end

    y_max = (a * n + b) / m

    return res if y_max == 0

    x_max = (m * y_max - b + a - 1) / a
    res += (n - x_max) * y_max + floor_sum(y_max, a, m, a * x_max - m * y_max + b)
    res
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
ac-library-rb-0.5.2	lib_lock/ac-library-rb/floor_sum.rb
ac-library-rb-0.5.1	lib_lock/ac-library-rb/floor_sum.rb
ac-library-rb-0.5.0	lib_lock/ac-library-rb/floor_sum.rb