322. 零钱兑换

class Solution:
    def coinChange(self, coins: List[int], amount: int) -> int:
        dp =[inf]*(amount+1)
        dp[0]=0 
        for i in range(1, amount+1):
            for j in coins:
                if i>=j:
                    dp[i] = min(dp[i],dp[i-j]+1)
        return   dp[-1] if dp[-1]!=inf  else -1