123_best_time_to_buy_and_sell_stock_3.py

'''
Say you have an array for which the ith element is the price of a given stock on day i.

Design an algorithm to find the maximum profit. You may complete at most two transactions.

Note:
You may not engage in multiple transactions at the same time (ie, you must sell the stock before you buy again).
'''
class Solution(object):
    def maxProfit(self, prices):
        """
        :type prices: List[int]
        :rtype: int
        """

s = Solution()
assert s.maxProfit([]) == 0
assert s.maxProfit([]) == 0

print "All test passes!"