Integer Break

Problem: Integer Break

For 7, it's 322. For numbers following 7, if the previous product is even, replace a 2 with 3. If not, replace a 3 with 4 (2*2).

Code in Python:

class Solution(object):
    def integerBreak(self, n):
        """
        :type n: int
        :rtype: int
        """
        res = [0, 0, 1, 2, 4, 6, 9]
        for i in xrange(7, n+1):
            if res[-1] % 2:
                res.append(res[-1]/3*4)
            else:
                res.append(res[-1]/2*3)
        return res[n]