You are given an array of stock prices where is the price of a given stock on the 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.
Write a python program that will return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.
Input: prices = [7,1,5,3,6,4] Output: 5 # 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.
Input: prices = [7,6,4,3,1] Output: 0 # Explanation: In this case, no transactions are done and the max profit = 0.
Fill in the function below to complete your program:
from typing import List def buy_and_sell_stock(prices: List[int]) -> int: """Write your code here""" return None