Union Find
21 problems
Union-Find (Disjoint Set Union) tracks connected components efficiently. Operations: Find (with path compression) and Union (by rank). Achieves near-O(1) per operation (O(α(n)) amortized). Classic uses: Kruskal's MST, detecting undirected graph cycles, and grouping equivalent elements.
- 684.Redundant ConnectionMedium
- 778.Swim in Rising WaterHard
- 827.Making A Large IslandHard
- 839.Similar String GroupsHard
- 928.Minimize Malware Spread IIUnknown
- 947.Most Stones Removed with Same Row or ColumnMedium
- 959.Regions Cut By SlashesUnknown
- 1061.Lexicographically Smallest Equivalent StringMedium
- 1319.Number of Operations to Make Network ConnectedMedium
- 1579.Remove Max Number of Edges to Keep Graph Fully TraversableUnknown
- 1733.Minimum Number of People to TeachUnknown
- 1905.Count Sub IslandsUnknown
- 1970.Last Day Where You Can Still CrossUnknown
- 1971.Find if Path Exists in GraphEasy
- 2092.Find All People With SecretUnknown
- 2493.Divide Nodes Into the Maximum Number of GroupsHard
- 2503.Maximum Number of Points From Grid QueriesHard
- 2658.Maximum Number of Fish in a GridMedium
- 2685.Count the Number of Complete ComponentsMedium
- 3108.Minimum Cost Walk in Weighted GraphUnknown
- 3310.Remove Methods From ProjectUnknown