class Solution: def maxProfit(self, prices: List[int]) -> int: ans = 0 min_price = prices[0] for p in prices[1:]: 从第二天开始遍历 if p > min_price: 只有当前价格 > 最低价时才计算利润 ans = max(ans, p - min_price) else: 否则更新最低价 min_price = p return ans