Look for these signals in the problem:
- "Are X and Y connected": queries after union operations: Union Find answers connectivity in near .
- "Number of connected components": Count distinct roots after processing all edges.
- "Detect cycle" in undirected graph: If union finds same root, edge creates cycle.
- Dynamic connectivity: When edges are added over time and you need connectivity queries throughout.
- "Group" or "merge" accounts/elements: When merging sets based on shared properties.