Lecture 3 - Dijkstra's Refinement

Question 1

What needs to be added to dijkstra’s to find a minimum spanning tree?

Answer 1

Each vertex should have a bestTv attribute. This is a tree vertex for which wt (p->q) is minimised

Question 2

What is the complexity of this algorithm?

Answer 2

O(n^2) overall

• initialisation is O(n) like in Prim-Jarnik
• outer while loop is executed n-1 times
• O(n) to find minimum and adjoin to tree
• updating tvs is O(n)

Question 3

Will proof of correctness be part of the exam.

Answer 3

No, the proof will not be examined. This is video 3 of lecture 3.