Algorithm Interview 2026: Algorithms — How to Think, Not What to Memorize

Sorting and binary search hide inside half your interview solutions. Master every sort variant, binary search on answer space, and the 3 patterns that turn O(n²) into O(n log n).

Every recursive solution is secretly a tree traversal. Once you see that, pruning becomes obvious. Master the backtracking template and 4 problem types found in every interview.

DP is not about memorizing problems. Recognize two signals — optimal substructure and overlapping subproblems — then apply 6 patterns that make DP finally approachable.

Greedy algorithms are easy to implement but hard to justify. Learn the exchange argument, the 5 greedy patterns, and when greedy fails so you know to reach for DP instead.

Divide and conquer is behind merge sort, binary search, and fast power. Master the split-solve-merge pattern and the Master Theorem for complexity analysis in one focused post.