https://wid-blog.github.io/en/tags/graph/Recent content in Graph on wid's blogHugoenSat, 04 Jul 2026 00:00:00 +0000https://wid-blog.github.io/en/posts/tech/algorithm/union-find/Sat, 04 Jul 2026 00:00:00 +0000https://wid-blog.github.io/en/posts/tech/algorithm/union-find/Union-Find gives each group a root representative and decides whether two elements share a group. The unoptimized version stretches find to O(N) on chain trees; path compression and union by rank make it practically constant.https://wid-blog.github.io/en/posts/tech/algorithm/topological-sort/Fri, 03 Jul 2026 00:00:00 +0000https://wid-blog.github.io/en/posts/tech/algorithm/topological-sort/Kahn’s BFS for topological sort repeatedly takes nodes with zero in-degree, and cycle detection comes along without extra logic. The mechanism, the Course Schedule problems, and the selection criteria against DFS post-order.