class Solution:

    def maxProfit(self, prices: List[int]) -> int:

        """
        Returns the maximum profit earned

        Arguments:
            prices:

        Returns:

        Notes
        -----
        The problem translates to finding maximum profit which is
        difference of the current price and minimum seen so far.
        It is an optimisation over the brute-force aproach where
        one does not need to determine minimum so far everytime
        """

        min_price = float('inf')
        max_profit = float('-inf')

        for i in range(len(prices)):

            # check for minimum price
            if prices[i] < min_price:
                min_price = prices[i]

            # check condition for max profit
            max_profit_sell_today = prices[i] - min_price
            if max_profit_sell_today > max_profit:
                max_profit = max_profit_sell_today

        return max_profit