Greedy Best First Search-Artificial Intelligence-Unit – 1 -Problem Solving -Informed Searching

Unit – 1 – Problem Solving
Informed Searching Strategies - Greedy Best First Search
Greedy best-first search algorithm always selects the path which appears best at that moment.
It is the combination of depth-first search and breadth-first search algorithms.
It uses the heuristic function and search.
With the help of best-first search, at each step, we can choose the most promising node.
In the best first search algorithm, we expand the node which is closest to the goal node and the minimum cost is estimated by heuristic function

The evaluation function is f(n) = h(n)
Were, h(n)= estimated cost from node n to the goal.

Greedy search ignores the cost of the path that has already been traversed to reach n
Therefore, the solution given is not necessarily optimal
Greedy best-first search can start down an infinite path and never return to try other possibilities, it is incomplete
Because of its greediness the search makes choices that can lead to a dead end; then one backs up in the search tree to the deepest unexpanded node
Greedy best-first search resembles depth-first search in the way it prefers to follow a single path all the way to the goal, but will back up when it hits a dead end
The quality of the heuristic function determines the practical usability of greedy search

Greedy search is not optimal
Greedy search is incomplete without systematic checking of repeated states.
In the worst case, the Time and Space Complexity of Greedy Search are both O( b m ),
Where
b is the branching factor and
m the maximum path length

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[karthikr]

shouldn't we include A's h(n) values why summing up at end?

[Mexton-qstd]

personally i have really enjoyed this class, u made it so easy for me to understand, thank you

[pruthvisavadi]

Mam in the case of 2nd example uh took 'c' as a path after that 'D' & 'E' are already visited but can we visit 'F' or not ?mam

[Lee-uwlr]

Why will GBFS back up if it meets a dead end? Then how will GBFS get stuck in a loop then? I hope you can answer my question

[balachandar]

how to find the cost between start A to B, C, E, asking about the values 118, 140, 75 how did it came??

[senthilkumarsadhasivam]

Good work, well explained, keep doing

[Neeharika_Sompalli_]

good but
better to explain the calculation of h(n)

[edattabhavani]

is best first search and greedy search is same or different?

[lutwetweshadrackduncan]

What happens if two nodes have the same heuristic value?

[khan]

Madam Is This Table Will Give In Exam Section??