Graphs

• A* Search

  A* pathfinding on a weighted grid

• Bellman Ford

  Shortest paths allowing negative edge weights

• Clone Graph

  Deep copy an undirected graph

• Course Schedule

  Determine if all courses can be finished (cycle detection)

• Dijkstra

  Single-source shortest paths with non-negative edge weights

• Geohash Grid

  Geohash encoding, decoding, and neighbor lookup

• KD-Tree

  K-dimensional tree for nearest neighbor search

• Minimum Spanning Tree

  Minimum spanning tree: Kruskal's and Prim's algorithms

• Network Delay Time

  Time for a signal to reach all nodes (Dijkstra variant)

• Network Flow

  Maximum flow via Edmonds-Karp (BFS-based Ford-Fulkerson)

• Number Of Islands

  Count islands in a 2D grid of '1's (land) and '0's (water)

• Topological Sort

  Topological ordering of a directed acyclic graph (DAG)

• Word Ladder

  Shortest transformation sequence from beginWord to endWord