One question from each format, in two minutes.

Two Sum Pattern Recognition

Given an array of integers and a target sum, which approach is most efficient for finding two numbers that add up to the target?

• a.Nested loops checking every pair - O(n²)
• b.Sort then use two pointers - O(n log n)
• c.Hash map to store complements - O(n)
• d.Binary search for each element - O(n log n)