DFS vs BFS

Depth First Search (DFS) Breadth First Search (BFS)&Uniform Cost Search (UCS) Vichhaiy SEREY (ID: 5938445)

Professors:Ananta Srisuphab Piyanuch Silapachote 9/28/2016ITCS6611

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OutlineWhat they areDFS and BFSTake a look at a scenarioTest Scenario 1Test Scenario 2Let talk about UCSConclusion9/28/2016ITCS6612

What they areThey both are search algorithms which can be used to search path to a vertex (node) in the tree or unweighted graph domain.

9/28/2016ITCS6613DFS:Implement with Stack (LIFO)It attempts to search as far as possible to find the goal nodeIt cares to reach the goal, but it doesnt care if the path is shorterIf the goal is deep, it is good

BFS:Implement with Queue (FIFO)Search layer by layer, as close as possibleIf the goal is not far, the BFS is goodIf you care the shorter path to the goal, it is goodBut yes, it consumes more time and memory as the goal is deeperTheyre good for their scenarios

Consider this tree:9/28/2016ITCS6614ABCDEIFHJKMLN

Take a look in one scenarioSuppose a company has many branches (routers) and all branches are formed topology as showing below.We want to know which path host A sends data to host B9/28/2016ITCS6615

DFS & BFS

DFSBFS#7#5

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DFSBFS9/28/2016ITCS6617

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Try from A to SR

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same

About Uniform Cost Search (UCS)It is one of the best search algorithm compare to DFS or BFS because it determines the best path through the actual path cost NOT just count number of nodes.

implement with priority queue9/28/2016ITCS6619

Uniform Cost Search Algorithm

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Test old scenario: routers

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ConclusionDFS uses Stack and BFS uses QueueDFS tries as deep as possible & BFS tries layer by layerDFS is simpler compared to BFSWe cannot say which one is better. It depends on which scenario we want to apply.If the goal is deep, DFS would be betterIf the goal is not far, BFS would be better

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