https://wid-blog.github.io/en/tags/data-structure/Recent content in Data Structure 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.