CODEWITHSUNDEEP
algorithmsearchdata-structuresartificial-intelligence
Sahil
Sahil

Reputation: 9480

How to obtain the path in the "uniform-cost search" algorithm?

I have been going through the algorithm of uniform-cost search and even though I am able to understand the whole priority queue procedure I am not able to understand the final stage of the algorithm.

If we look at this graph, after applying the algorithm I will have the minimum distance for each node, but suppose I want to know the path between A to G (just like the example), how will I compute that?

Upvotes: 8

Views: 38753

Answers (2)

Zeta
Zeta

Reputation: 105886

Usually you start with a infinite total cost for every node that hasn't been explored yet. Then you can adjust the algorithm a little bit to save the predecessor:

for each of node's neighbours n
    if n is not in explored
        if n is not in frontier
            frontier.add(n)
            set n's predecessor to node
        elif n is in frontier with higher cost
            replace existing node with n
            set n's predecessor to node

Afterwards you can just check the sequence of predecessors, starting at your goal.

Upvotes: 14

jayant singh
jayant singh

Reputation: 889

Visit for more info https://www.youtube.com/watch?v=9vNvrRP0ymw

Insert the root into the queue
While the queue is not empty
      Dequeue the maximum priority element from the queue
      (If priorities are same, alphabetically smaller path is chosen)
      If the path is ending in the goal state, print the path and exit
      Else
            Insert all the children of the dequeued element, with the cumulative costs as priority

Upvotes: 0

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