new_contents: class Solution(object):
      def PredictTheWinner(self, nums):
          """
          :type nums: List[int]
          :rtype: bool
          """
          dp = dict()
          def top_down(start, end):
              if start == end:
                  dp[start, end] = 0
              elif (start, end) not in dp:
                  dp[start, end] = max(nums[start] - top_down(start + 1, end), nums[end - 1] - top_down(start, end - 1))
              return dp[start, end]
  
          return top_down(0, len(nums)) >= 0
  
subject: Add py solution for 486. Predict the Winner