[LeetCode] 0121. Best Time to Buy and Sell Stock

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Easy

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 choose a different days 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:

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.

Example 2:

Input: prices = [7,6,4,3,1]
Output: 0
Explanation: In this case, no transactions are done and the max profit = 0.

Constraints:

1 <= prices.length <= 10 ⁵
0 <= prices[i] <= 10 ⁴

Python

				
					# time complexity: O(n) # space complexity: O(1) from typing import List class Solution(object): def maxProfit(self, prices: List[int]) -> int: profit, smallestPrice = 0, 99999 for price in prices: if price < smallestPrice: smallestPrice = price else: profit = max(profit, price - smallestPrice) return profit PriceList = [7, 1, 5, 3, 6, 4] solution = Solution() print(solution. maxProfit(PriceList))

Easy

Python

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