← Back to the arrays page
Sorted Array
Order unlocks logarithmic search and linear merging — most classic array algorithms assume or create sortedness.
What to know
- Binary search needs random access — it is an array algorithm, not a list algorithm.
- Two pointers from both ends solve pair-sum problems without extra memory.
- Merging two sorted arrays is the heart of merge sort and external sorting.
In the wild: Database indexes, sorted ID lists in search engines, time-series query windows.
Algorithms to reach for
Binary search
O(log n)Find element or insertion point
Two pointers (opposite ends)
O(n)Two-sum sorted, container with most water
Merge of sorted arrays
O(n + m)Combine sorted runs stably
Practice problems — with full guides
Each problem has its own page: progressive hints, how to approach it, and the full solution.