old_contents: """Leetcode 122. Best Time to Buy and Sell Stock II
  Easy
  
  URL: https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/
  
  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 as many transactions as you like
  (i.e., buy one and sell one share of the stock multiple times).
  
  Note: You may not engage in multiple transactions at the same time
  (i.e., you must sell the stock before you buy again).
  
  Example 1:
  
  Input: [7,1,5,3,6,4]
  Output: 7
  Explanation: Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4.
               Then buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3.
  
  Example 2:
  Input: [1,2,3,4,5]
  Output: 4
  Explanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.
               Note that you cannot buy on day 1, buy on day 2 and sell them later, as you are
               engaging multiple transactions at the same time. You must sell before buying again.
  
  Example 3:
  Input: [7,6,4,3,1]
  Output: 0
  Explanation: In this case, no transaction is done, i.e. max profit = 0.
  """
  
  class Solution(object):
      def maxProfit(self, prices):
          """
          :type prices: List[int]
          :rtype: int
          """
          pass
  
  
  def main():
      pass
  
  
  if __name__ == '__main__':
      main()
  
new_contents: """Leetcode 122. Best Time to Buy and Sell Stock II
  Easy
  
  URL: https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/
  
  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 as many transactions as you like
  (i.e., buy one and sell one share of the stock multiple times).
  
  Note: You may not engage in multiple transactions at the same time
  (i.e., you must sell the stock before you buy again).
  
  Example 1:
  Input: [7,1,5,3,6,4]
  Output: 7
  Explanation: Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4.
               Then buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3.
  
  Example 2:
  Input: [1,2,3,4,5]
  Output: 4
  Explanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.
               Note that you cannot buy on day 1, buy on day 2 and sell them later, as you are
               engaging multiple transactions at the same time. You must sell before buying again.
  
  Example 3:
  Input: [7,6,4,3,1]
  Output: 0
  Explanation: In this case, no transaction is done, i.e. max profit = 0.
  """
  
  class Solution(object):
      def maxProfit(self, prices):
          """
          :type prices: List[int]
          :rtype: int
          """
          profit = 0
          # Iterate each day and compare it with yesterday to get profit.
          for i in range(1, len(prices)):
              profit += max(prices[i] - prices[i - 1], 0)
          return profit
  
  
  def main():
      # Ans: 7.
      prices = [7,1,5,3,6,4]
      print Solution().maxProfit(prices)
  
      # Ans: 4.
      prices = [1,2,3,4,5]
      print Solution().maxProfit(prices)
  
      # Ans: 0.
      prices = [7,6,4,3,1]
      print Solution().maxProfit(prices)
  
  
  if __name__ == '__main__':
      main()
  
subject: Complete iter sol