37 DSA patterns
37 patterns in the catalog. Full guides include multi-language templates, mental models, and curated write-up paths; some advanced patterns are still stubs. The chip is your status (Not started / In progress / Completed); the line under each card is how many on-site guides exist.
Showing 1 to 9 of 37
Sliding Window
Longest, shortest, or valid contiguous ranges over arrays and strings.
6/6 guides · template
Two Pointers
Sorted arrays, pair conditions, or coordinated movement from both ends.
6/6 guides · template
Fast & Slow Pointers
Linked-list cycles, middle nodes, and fixed pointer gaps.
6/6 guides · template
Binary Search
Halve a sorted or monotonic search space until you pin the answer.
6/6 guides · template
Binary Search on Answer
Binary search the answer value itself; check if a candidate is feasible in linear time.
6/6 guides · template
Hashing
O(1) average lookup, frequency counting, grouping, and complement checks.
6/6 guides · template
Prefix Sum
Precompute running sums so any range sum is O(1); pair with maps for subarray sum counts.
6/6 guides · template
Difference Array
Range updates in O(1); rebuild the array with a prefix pass.
6/6 guides · template
Monotonic Stack
Next greater/smaller, histogram rectangles, and temperature waits.
6/6 guides · template