The Gateway to Computer Science Excellence
+23 votes

Suppose we run Dijkstra’s single source shortest path algorithm on the following edge-weighted directed graph with vertex $P$ as the source.

In what order do the nodes get included into the set of vertices for which the shortest path distances are finalized?

  1. $P,Q,R,S,T,U$
  2. $P,Q,R,U,S,T$
  3. $P,Q,R,U,T,S$
  4. $P,Q,T,R,U,S$
in Algorithms by Veteran (52.2k points)
edited by | 2.6k views

2 Answers

+24 votes
Best answer

Answer is (B). In Dijkstra's algorithm at each point we choose the smallest weight edge which starts from any one of the vertices in the shortest path found so far and add it to the shortest path.

by Junior (775 points)
edited by
Ans (C) is also possible in this case.. so, what is the answer ? confused about it.
(c )can not be an answer  according to dijikstras algorithm

reaching node R  , edge to S and U from R is relaxed which gives node S value - 4 and node U value as 3 therefore we wil choose U now and after that  S and at the and T
Why we prefer S-T(cost to reach from P is 8) over P-T(Cost is 7)?

Is in Dijkstra from a vertex only one outgoing edge(of minimum weight) is allowed?
+7 votes

Answer will be "B" 

by Loyal (8.5k points)

Related questions

Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
50,647 questions
56,461 answers
100,240 users