EasyArraysAI interview only
Best Time to Buy and Sell Stock
Asked atamazongooglemicrosoftbloomberggoldman-sachs
01 · Problem
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.
02 · Examples
Example 01
Input
prices = [7,1,5,3,6,4]
Output
5
Buy on day 2 (price = 1) and sell on day 5 (price = 6). Profit = 6 - 1 = 5. Selling on day 3 for profit 5 - 1 = 4 is less optimal.
Example 02
Input
prices = [7,6,4,3,1]
Output
0
Prices are strictly decreasing, so no profitable transaction is possible. Return 0.
03 · Constraints
- 011 <= prices.length <= 105
- 020 <= prices[i] <= 104
04 · Optimal complexity
- Time
- O(n)
- Space
- O(1)
05 · Two ways to work on it
Practice it alone or rehearse it as an interview.
Practice Mode gives you an editor and test runs, nothing else. AI Interview Mode puts a voice interviewer on the other side, adds a clock, and ends with a scored summary of the round.