Changelog
October 2026
Recursion · Coding Question
Find every combination of candidates that sums to a target, reusing numbers as often as you like (LeetCode #39). Asked at Amazon, Airbnb and 19 more companies.
Two Pointers · Coding Question
Reverse the order of the words in a character array, working in place (LeetCode #186). Asked at Amazon, Microsoft and 7 more companies.
Rotate Array
NewArrays & Hashing · Coding Question
Rotate an array to the right by k steps (LeetCode #189). Asked at Cisco, PayPal and 7 more companies.
Recursion · Coding Question
Find every unique combination of candidates that sums to a target, using each number at most once (LeetCode #40). Asked at Ripple, Nordstrom and 3 more companies.
Graphs · Coding Question
Given pairs of indices you may swap any number of times, return the lexicographically smallest string you can reach (LeetCode #1202).
Path Sum IV
NewTrees · Coding Question
Sum every root-to-leaf path of a binary tree that is encoded as an array of three-digit integers (LeetCode #666).
Bit Manipulation · Coding Question
Generate every valid abbreviation of a word, where non-adjacent substrings are replaced by their lengths (LeetCode #320).
Graphs · Coding Question
Find the most stones you can remove when a stone can only go if another shares its row or column (LeetCode #947).
Recursion · Coding Question
Return every distinct palindrome that can be formed by rearranging the characters of a string (LeetCode #267).
Graphs · Coding Question
Find the highest-value path that starts and ends at node 0 within a time limit, counting each visited node once (LeetCode #2065).
Trees · Coding Question
Rebuild trace trees from a flat list of spans and their parent ids, and return each span with its depth.
Graphs · Coding Question
Group employees who share an interest, directly or through a chain of colleagues, and return every group.
Tries · Coding Question
Remove every string that is a prefix of another string in the list, keeping the rest in their original order.
Arrays & Hashing · Coding Question
Pick three items in index order with strictly increasing prices so that their combined profit is as large as possible.
Graphs · Coding Question
Cluster images that are linked, directly or through other images, by similarity scores at or above a threshold.
Heaps · Coding Question
Total each customer's purchases and return the k customers with the least revenue, lowest first.
Graphs · Coding Question
Given child-parent edges describing a forest, return the root of the tree with the most nodes.
Recursion · Coding Question
Recursively generate every outcome of rolling n dice with m faces each.
