1582 articles
Master advanced Dijkstra: state augmentation, K-stop limits, two-cost optimisation, k-th shortest paths, and modified relaxation. The interview pattern behind LeetCode 787, 1928, and 1976, asked at Google, Amazon, and Meta.
Master bipartite checking and graph coloring: a single BFS or DFS pass that 2-colors a graph and proves it is bipartite, or finds an odd cycle. The pattern behind LeetCode 785 Is Graph Bipartite and LeetCode 886 Possible Bipartition, asked at Google, Meta, and Amazon.
Master LeetCode 1584 Min Cost to Connect All Points: model the n^2 implicit edges as a complete graph, then run Prim's MST in O(n^2) without ever materialising the edge list. A FAANG-favourite interview question at Amazon, Google, and Meta that tests whether you can spot a Minimum Spanning Tree behind a geometry prompt.
Solve the bottleneck shortest path problem: find a route from source to destination that minimises the maximum edge weight on the path. Combines binary search on the answer with BFS connectivity checks in O((V+E) log W) — a FAANG interview pattern asked at Google and Amazon, and the foundation behind LeetCode 1102 Path With Maximum Minimum Value.
Master LeetCode 1976 Number of Ways to Arrive at Destination: extend Dijkstra to count the number of distinct shortest paths simultaneously, returning the count modulo 10^9+7. A FAANG-favourite shortest-path counting interview question asked at Google, Amazon, and Meta.