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aimacode / aima-python

Python implementation of algorithms from Russell And Norvig's "Artificial Intelligence - A Modern Approach"
MIT License
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alpha beta pruning is incomplete #34

Closed GoogleCodeExporter closed 8 years ago

GoogleCodeExporter commented 8 years ago 
the use of argmax() for the first max node in the alpha beta pruning searches 
will not allow alpha pruning to be updated among the min successors of the 
initial max mode.  code in question:

    # Body of alphabeta_search:
    return argmax(game.actions(state),
                  lambda a: min_value(game.result(state, a),
                                      -infinity, infinity))

alpha will always be -infinity instead of a value discovered in a previous min 
child/successor.

Original issue reported on code.google.com by chasmosa...@gmail.com on 22 Nov 2012 at 10:16

darkcoderrises commented 8 years ago

If no one is working on this, could I?

Chipe1 commented 8 years ago

This should fix it. #70 EDIT - The return value is wrong. Working on it right now. EDIT - Fixed in #123