The Branching Factor of Regular Search Spaces

Manyproblems,such as the sliding-tile puzzles, generate searchtrees wheredifferent nodeshavedifferent numbersof children, in this case dependingon the position of the blank. Weshowhowto calculate the asymptotic branchingfactors of such problems,and howto efficiently computethe exact numbersof nodes at a givendepth. Thisinformationis importantfor determiningthe complexityof various searchalgorithms onthese problems.In additionto the sliding-tile puzzles, wealso apply our technique to Rubik'sCube. Whileour techniquesare fairly straightforward, the literature is full of incorrectbranchingfactorsfor these problems,andthe errors in several incorrect methods are fairly subtle.

• Type: Conference
• Year: 1998
• Where: AAAI
• Authors: Stefan Edelkamp, Richard E. Korf
• Keywords: AAAI 1998, Complexityof Various Searchalgorithms, Exact Numbersof Nodes, Intelligent Agents, Sliding-tile Puzzles