# 题目

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 choosing a different day in the future to sell that stock.

Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.

Example 1:

Example 2:

Constraints:

• 1 <= prices.length <= 105
• 0 <= prices[i] <= 104