动态规划_leetcode312

#coding=utf-8

# 递归
class Solution1(object):
    def maxCoins(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        self.res = 0

        if not nums:
            return self.res

        self.res = self.getMaxValue(nums)

        print self.res
        return self.res

    def getMaxValue(self,nums):

        nLen = len(nums)

        if nLen == 1:
            return nums[0]

        maxRes = 0

        for i in range(nLen):

            if i == 0 :
                temp = nums[0:]
                temp.pop(i)
                maxRes = max(maxRes,nums[i]*nums[i+1]+self.getMaxValue(temp))


            elif i == nLen-1:
                temp = nums[0:]
                temp.pop(i)
                maxRes = max(maxRes, nums[i] * nums[i-1]+self.getMaxValue(temp))


            else:
                temp = nums[0:]
                temp.pop(i)
                maxRes = max(maxRes, nums[i-1]* nums[i]*nums[i+1]+ self.getMaxValue(temp))


        return maxRes


# 记忆化递归

class Solution2(object):
    def maxCoins(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        self.res = 0

        if not nums:
            return self.res

        self.memo = {}
        self.res = self.getMaxValue(nums)


        print self.res
        return self.res

    def getMaxValue(self,nums):

        nLen = len(nums)

        if nLen == 1:

            key = tuple(nums)
            self.memo[key] = nums[0]
            return nums[0]


        key = tuple(nums)

        if self.memo.has_key(key):
            return self.memo[key]

        maxRes = 0

        for i in range(nLen):

            if i == 0 :
                temp = nums[0:]
                temp.pop(i)
                maxRes = max(maxRes,nums[i]*nums[i+1]+self.getMaxValue(temp))


            elif i == nLen-1:
                temp = nums[0:]
                temp.pop(i)
                maxRes = max(maxRes, nums[i] * nums[i-1]+self.getMaxValue(temp))


            else:
                temp = nums[0:]
                temp.pop(i)
                maxRes = max(maxRes, nums[i-1]* nums[i]*nums[i+1]+ self.getMaxValue(temp))

        self.memo[key] = maxRes
        return maxRes


#动态规划
#  见解题报告
class Solution3(object):
    def maxCoins(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """





s = Solution2()

n1 = [3,1,5,8]


n2 = [5,8]

n3 = [3,5,8]

n4 = [7,9,8,0,7,1,3,5,5,2,3]

n5 = [8,3,4,3,5,0,5,6,6,2,8,5,6,2,3,8,3,5,1,0,2]

s.maxCoins(n4)