121. Best Time to Buy and Sell Stock

 1class Solution:
 2    def maxProfit(self, prices: List[int]) -> int:
 3
 4        lowest = prices[0]
 5        profit = 0
 6
 7        for price in prices:
 8            lowest = min(lowest, price)
 9            profit = max(profit, price - lowest)
10
11        return profit