RosettaCodeData/Task/Polynomial-long-division/Ruby/polynomial-long-division-3.rb
2015-02-20 00:35:01 -05:00

29 lines
778 B
Ruby

def polynomial_division(f, g)
if g.length == 0 or (g.length == 1 and g[0] == 0)
raise ArgumentError, "denominator is zero"
end
return [[0], f] if f.length < g.length
q, n = [], f.dup
while n.length >= g.length
q << Float(n[0]) / g[0]
n[0, g.length].zip(g).each_with_index do |pair, i|
n[i] = pair[0] - q[-1] * pair[1]
end
n.shift
end
q = [0] if q.empty?
n = [0] if n.empty?
[q, n]
end
f = [1, -12, 0, -42]
g = [1, -3]
q, r = polynomial_division(f, g)
puts "#{f} / #{g} => #{q} remainder #{r}"
# => [1, -12, 0, -42] / [1, -3] => [1.0, -9.0, -27.0] remainder [-123.0]
g = [1, 1, -3]
q, r = polynomial_division(f, g)
puts "#{f} / #{g} => #{q} remainder #{r}"
# => [1, -12, 0, -42] / [1, 1, -3] => [1.0, -13.0] remainder [16.0, -81.0]