This backtracking question combines 4 patterns in one. (and Bloomberg is known for asking it) Given a 2-D grid of characters `board` and a string `word`, return true if `word` is present in the grid, ...

Given an integer array nums that may contain duplicates, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any order. Intuition: ...

You must first learn trees before you learn: - Backtracking - Graphs - Implicit Graphs Because once you learn trees, everything after stops feeling random. Here's the order we recommend: 1) Binary ...

Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target. Each number in candidates may ...