Best_Time_to_Buy_and_Sell_Stock.py

# Question: Given a list of stock prices each day, determine the most profit you could make buying and selling the stock once
# Solution: Loop through finding the minimum price each time, and then the max profit. This works because the profit will be negative on days where the stock goes down
# Difficulty: Easy
# Time Complexity: O(n)
# Space Complexity: O(n)

from typing import List

def maxProfit(prices: List[int]) -> int:
  # Initialize lowestPrice to MAX_INT and mostProfit to be 0 
  lowestPrice, mostProfit = float('inf'), 0

  for i, price in enumerate(prices):
      # In each loop determing the lowest price, and the max profit by subtracting the current price by the lowest known one 
      lowestPrice = min(lowestPrice, price)
      mostProfit = max(price - lowestPrice, mostProfit)
      
  return mostProfit