2023-08-11 08:17:35 +0000 UTC

class Solution:
    def change(self, amount: int, coins: List[int]) -> int:
        n = len(coins)
        dp = [[0] * (amount + 1) for _ in range(n + 1)]
        for i in range(n):
            dp[i][0] = 1

        for i in range(n - 1, -1, -1):
            for j in range(1, amount + 1):
                if coins[i] > j:
                    dp[i][j] = dp[i + 1][j]
                else:
                    dp[i][j] = dp[i + 1][j] + dp[i][j - coins[i]]

        return dp[0][amount]