Leetcode coin change 2

class Solution:
    def coinChange(self, coins: List[int], amount: int) -> int:
        if len(coins) == 1:
            if amount % coins[0] == 0:
                return amount // coins[0]
            else:
                return -1
        elif amount == 0:
            return 0

        res = []

        ans = self.numCoins(coins, amount)

        return ans

    def numCoins(self, coins, amount, memo={}):
        if amount in memo:
            return memo[amount]
        if amount == 0:
            return 1
        elif amount < 0:
            return 0
        else:
            min_val = amount // min(coins)

            for coin in coins:
                if (amount - coin) >= 0:
                    min_val = min(min_val, 1 + self.numCoins(coins, amount-coin, memo))

            memo[amount] = min_val

            return min_val