30-seconds-of-code/snippets/gcd.md

gcd

Calculates the greatest common divisor between two or more numbers/arrays.

The helperGcdfunction uses recursion. Base case is when y equals 0. In this case, return x. Otherwise, return the GCD of y and the remainder of the division x/y.

Uses the reduce function from the inbuild module functools. Also defines a method spread for javascript like spreading of arrays.

    from functools import reduce
	def spread(arg):
         ret = []
         for i in arg:
           if isinstance(i,list):
             ret.extend(i)
           else:
             ret.append(i)
         return ret
    def gcd(*args):
        numbers = []
        numbers.extend(spread(list(args)))
        def helperGcd(x,y):
            return x if not y else gcd(y,x%y)
        return reduce((lambda x,y : helperGcd(x,y)),numbers)