- You are given an array
prices[i]is the price of a given stock on the ith day.
- You want to maximize your profit by choosing a single day to buy one stock and choosing a different day to sell that stock in the future.
- Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.
- This challenge corresponds to LeetCode #121.
1 <= prices.length <= 105
0 <= prices[i] <= 104
prices = [7, 1, 5, 3, 6, 4]
Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
prices = [7, 6, 4, 3, 1]
Explanation: In this case, no transactions are done, and the max profit = 0.
Below is my solution and some test cases. This solution has a linear time complexity O(n) and a constant space complexity O(1), where n is the length of the input list.