[Leetcode] 121. Best Time to Buy and Sell Stock

Problem Link: https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/

Best Time to Buy and Sell Stock - LeetCode

Solution 1. Two Pointer

Time: $O(N)$

Space: $O(1)$ 

class Solution(object):
    def maxProfit(self, prices):
        """
        :type prices: List[int]
        :rtype: int
        """

        buy = 0; sell = 1
        max_profit = 0
        
        for sell, price in enumerate(prices):
            profit = price - prices[buy]
            if profit < 0:
                buy = sell
            else:
                max_profit = max(max_profit, profit)

        return max_profit