动态规划_leetcode322

标签：sel   style   int   return   lse   记忆   ns2   elf   continue   

# coding=utf-8

# 递归
class Solution1(object):
    def coinChange(self, coins, amount):
        """
        :type coins: List[int]
        :type amount: int
        :rtype: int
        """

        if not coins or amount <= 0:
            return -1

        self.res = amount
        self.flag = False
        self.tryChange(coins,amount,0)

        if self.flag:
            return self.res
        else:
            return -1

    def tryChange(self,coins,amount,ans):


        if amount == 0:
            self.flag = True
            self.res = min(self.res,ans)

        if amount < 0:
            return

        for i in range(len(coins)):
          self.tryChange(coins,amount-coins[i],ans+1)






# s = Solution1()
#
# coins = [1, 2, 5]
# amount = 11
#
# coins1 = [2]
# amount1 = 3
#
# print s.coinChange(coins1,amount1)


# 记忆化递归
class Solution2(object):
    def coinChange(self, coins, amount):
        """
        :type coins: List[int]
        :type amount: int
        :rtype: int
        """

        if not coins or amount <= 0:
            return -1

        self.maxAmount = amount+1

        return self.tryChange(coins,amount)


    def tryChange(self,coins,amount):


        if amount == 0:
            return 0


        res = amount

        for i in range(len(coins)):

            if amount - coins[i]>=0:
                res = min(res,1 + self.tryChange(coins,amount-coins[i]))


        return res


# 记忆化递归 返回值不纯粹2
class Solution3(object):
    def coinChange(self, coins, amount):
        """
        :type coins: List[int]
        :type amount: int
        :rtype: int
        """

        if not coins or amount <= 0:
            return -1

        self.maxAmount = amount + 1

        return self.tryChange(coins, amount)

    def tryChange(self, coins, amount):

        if amount == 0:
            return 0

        if amount < 0:
            return -1

        res = amount

        for i in range(len(coins)):

            value = self.tryChange(coins, amount - coins[i])

            if value == -1:
                    continue
            else:
                res = min(res,1+value)


        return res



# 记忆化递归 返回值不纯粹2
class Solution4(object):
    def coinChange(self, coins, amount):
        """
        :type coins: List[int]
        :type amount: int
        :rtype: int
        """

        if not coins or amount <= 0:            return -1        self.maxAmount = amount + 1        self.res = self.maxAmount        return self.tryChange(coins, amount,0)    def tryChange(self, coins, amount,ans):        if amount == 0:            return ans        if amount < 0:            return -1        res = self.maxAmount        # res = amount        for i in range(len(coins)):            value = self.tryChange(coins, amount - coins[i],ans+1)            if value == -1:                    continue            else:                res = min(res,value)        return res# s = Solution4()## coins = [1, 2, 5]# amount = 11## coins1 = [2]# amount1 = 3## print s.coinChange(coins,amount)# 记忆化递归 返回值不纯粹2class Solution5(object):    def coinChange(self, coins, amount):        """        :type coins: List[int]        :type amount: int        :rtype: int        """        if not coins or amount < 0:            return -1        if amount == 0:            return 0        self.maxAmount = amount + 1        self.memo = [-1 for i in range(amount+1)]        self.res = self.tryChange(coins, amount)        if self.res == self.maxAmount:            return -1        else:            return self.res    def tryChange(self, coins, amount):        if self.memo[amount] != -1:            return self.memo[amount]        if amount == 0:            return 0        res = self.maxAmount        # res = amount        for i in range(len(coins)):            if amount - coins[i] >=0:                res = min(res,1+self.tryChange(coins, amount - coins[i]))        self.memo[amount] = res        return res# s = Solution5()## coins = [1, 2, 5]# amount = 11## coins1 = [2]# amount1 = 3## coins2 = [112,149,215,496,482,436,144,397,500,189]# amount2 = 8480### print s.coinChange(coins2,amount2)# 动态规划class Solution6(object):    def coinChange(self, coins, amount):        """        :type coins: List[int]        :type amount: int        :rtype: int        """        if not coins or amount < 0:            return -1        if amount == 0:            return 0        maxAmount = amount + 1        memo = [maxAmount for i in range(amount+1)]        memo[0] = 0        for i in range(1,amount+1):            for j in coins:                if i - j >=0:                    memo[i] = min(memo[i],memo[i-j]+1)        if memo[amount] == maxAmount:            return -1        return memo[amount]s = Solution6()coins = [1, 2, 5]amount = 11coins1 = [2]amount1 = 3coins2 = [112,149,215,496,482,436,144,397,500,189]amount2 = 8480print s.coinChange(coins2,amount2)

动态规划_leetcode322

标签：sel   style   int   return   lse   记忆   ns2   elf   continue   

原文地址：https://www.cnblogs.com/lux-ace/p/10546616.html