What is the optimal time complexity of solving Best Time to Buy And Sell Stock?

The optimized solution achieves a time complexity of O(n) by using sorting, mathematical shortcuts, or hash table lookups.

What is the auxiliary space complexity for Best Time to Buy And Sell Stock?

The space complexity is O(n) since we only use a minimal/constant amount of extra memory for tracking variables (or auxiliary space if dynamic structures are allocated).

What are the typical edge cases we must handle in Best Time to Buy And Sell Stock?

Key edge cases include empty collections, negative or large bounds causing integer overflow, arrays with only one element, or inputs where target criteria are not met.

How can we optimize the brute force approach for Best Time to Buy And Sell Stock?

Brute force methods often inspect all possible combinations. We optimize this by sorting the input list to enable binary search, or tracking processed items in a set to avoid redundant nested loop lookups.

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Best Time to Buy And Sell Stock

Learn how to solve the 'Best Time to Buy And Sell Stock' problem. This detailed resource details brute force and optimized approaches.

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Problem Statement

Easy

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.

Write a function maxProfit(prices: List[int]) -> int.

Constraints

•1 <= len(prices) <= 10^5
•0 <= prices[i] <= 10^4

Examples

Example 1

Input

prices = [7, 1, 5, 3, 6, 4]

Output

Explanation

Buy on day 2 (price = 1) and sell on day 5 (price = 6). Profit = 6 - 1 = 5.

Example 2

Input

prices = [7, 6, 4, 3, 1]

Output

Explanation

No profitable transaction is possible since prices only decrease.

Need a Hint?

Maintain a sliding window boundary using two pointers. Expand the right boundary, and contract the left boundary if criteria are violated.

Edge Cases to Watch

Empty list or null input variables
Single item lists/arrays
Extremely large input bounds causing integer or stack overflow

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