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Grind 75.4 Best Time to Buy and Sell Stock

Solved at: 2022-07-13

Question

You are given an array prices where prices[i] is the price of a given stock on the ith 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.

Solution

class Solution:
def maxProfit(self, prices: List[int]) -> int:
if not prices:
return 0
minv = prices[0]
profit = 0
for i, price in enumerate(prices):
if price < minv:
minv = price
else:
if profit < prices[i] - minv:
profit = prices[i] - minv
return profit

I had to get a hint to keep the minimum value so far.

  • Time Complexity: O(n)O(n)
  • Space Complexity: O(1)O(1)

Results

Runtime

  • 1698 ms, faster than 38.38% of Python3 online submissions for Best Time to Buy and Sell Stock.

Memory Usage

  • 25 MB, less than 37.97% of Python3 online submissions for Best Time to Buy and Sell Stock.