Let be any connected, weighted, undirected graph.
- has a unique minimum spanning tree, if no two edges of have the same weight.
- has a unique minimum spanning tree, if, for every cut of , there is a unique minimum-weight edge crossing the cut.
Which of the following statements is/are TRUE?
View worked solution
Answer: C
Statement I is TRUE: If all edge weights in a connected, undirected graph are distinct, then has a unique minimum spanning tree (MST). This is a fundamental property of MSTs, which can be proved using the cycle property (the heaviest edge on any cycle cannot belong to any MST).
Statement II is TRUE: The Cut Property states that for any cut of a graph, the minimum-weight edge crossing the cut must belong to every MST. If for every cut there is a unique minimum-weight edge crossing it, then that specific edge must be included in every MST of . Since the choice of the minimum-weight edge for every cut is unique, there is no ambiguity or alternative choice at any step of constructing the MST (e.g., in Prim's or Kruskal's algorithm), which guarantees a unique MST.
Thus, both statements I and II are TRUE.
Free practice · Your answers on this page are not saved.
