Power as addition and iteration

power_addition.rb

# Question from Quora.com:
#  How do I write a program that computes "b" raised to power "n" using only addition and iteration?
#  http://www.quora.com/Computer-Programming/How-do-I-write-a-program-that-computes-b-raised-to-power-n-using-only-addition-and-iteration

# My solution in Ruby:

def power(b, n)
  result = 1
  n.times do
    result = Array.new(b, result).reduce(:+).to_i
  end
  result
end

# Or an alternative solution, without Array and reduce:

def mult (a, b)
  result = 0
  b.times{ result += a }
  result
end

def power(b, n)
  result = 1
  n.times{ result = mult(result, b) }
  result
end

# Which can be combined as:

def power(b, n)
  result = 1
  n.times do
    subtotal = 0
    b.times{ subtotal += result }
    result = subtotal
  end
  result
end