[Python手撕]零钱兑换（组合总数，需要去重）

class Solution:
    def change(self, amount: int, coins: List[int]) -> int:

        dp = [0]*(amount+1)
        dp[0] = 1
		# 从面值开始遍历是为了去重
        for c in coins:
            for i in range(c,amount+1):
                dp[i] += dp[i-c]
        return dp[-1]