BestTimeToSellStock.py

class Solution:
    def maxProfit(self, prices: List[int]) -> int:
        buy = prices[0]
        profit = 0
        n=len(prices)
        for i in range(1,n):
            if buy > prices[i]:
                buy = prices[i]
            elif prices[i]-buy > profit:
                profit = prices[i]-buy
        return profit