You are given an array
prices where prices[i] is the price of a given stock on the i-th day. You want to maximize your profit by choosing a single day to buy one stock and a different day in the future to sell that stock. Return the maximum profit you can achieve. If no profit is possible, return 0.Example 1
Inputprices = [7, 1, 5, 3, 6, 4]
Output5
ExplanationBuy on day 2 (price = 1) and sell on day 5 (price = 6); profit = 6 - 1 = 5.
Example 2
Inputprices = [7, 6, 4, 3, 1]
Output0
ExplanationPrices only fall — no profitable transaction is possible.
Constraints