method

int_from_prime_division

v1_9_2_180 - Show latest stable - 0 notes - Class: Prime

int_from_prime_division(pd) public

Re-composes a prime factorization and returns the product.

Parameters

`pd`	Array of pairs of integers. The each internal

pair consists of a prime number -- a prime factor --
and a natural number -- an exponent.

For [[p_1, e_1], [p_2, e_2], .…, [p_n, e_n]], it returns p_1**e_1 * p_2**e_2 * .… * p_n**e_n.

Prime.int_from_prime_division([[2,2], [3,1]]) #=> 12

Show source

# File lib/prime.rb, line 168
  def int_from_prime_division(pd)
    pd.inject(1){|value, (prime, index)|
      value *= prime**index
    }
  end