#dfs
7 articles
Graphs: Everything Is Connected
Graphs model maps, social networks, and dependencies. Learn how nodes and edges work, how to represent them, and what BFS and DFS unlock.
Graphs
Learn the graph data structure: adjacency lists vs matrices, BFS and DFS traversal, and the grid-as-graph reframe that cracks whole problem categories.
Binary Trees and Traversals
Master binary tree traversal — inorder, preorder, postorder, and level-order — and the recursive mindset that makes dozens of tree problems click instantly.
Topological Sort
Order the nodes of a DAG so every edge points forward — the algorithm that drives build systems, package managers, course schedulers, and anything else that lives and dies by dependency ordering.
Subsets, Permutations & Combinations
Generate subsets, permutations, and combinations with one choose/explore/un-choose backtracking template — and know exactly where 2^n and n! hit the wall.
DFS Patterns
Depth-first search is the backbone of cycle detection, flood fill, path enumeration, and clone graph — master the visited-set template, the 3-color trick, and when to reach for DFS over BFS.
Backtracking
Master the backtracking algorithm: the choose-explore-unchoose template, pruning that actually matters, and worked subsets, permutations, and N-queens.