05_uninformed_search2013

05_uninformed_search2013

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Unformatted text preview: n༆  Completeness: n༆  Time complexity: O(bm) Space complexity: O(bm) Optimality: No NO unless search space is finite. Time complexity: O(bm) Space complexity: O(bm) q༇  DFS evaluation q༇  n༆  n༆  q༇  NO unless search space is finite. Same issues as completeness Iterative Deepening Search (IDS) n༆  n༆  n༆  n༆  A strategy to find best depth limit l. Depth-Limited Search to depth 1, 2, … Expands from the root each time. Appears very wasteful, but combinatorics can be counter intuitive: N(DLS) = b + b2 +…+ bd-1 + bd = O(bd) N(IDS) = db + (d-1)b2 +…+ 2bd-1 + bd = O(bd) N(BFS) = b + b2 +…+ bd + bd+1 = O(bd+1) n༆  Example: For b = 10 and d = 5 N(DLS) = 111,111 N(IDS) = 123,456 N(BFS) = 1,111,100. 10 9/20/13 Iterative deepening search Evaluation of IDS function ITERATIVE_DEEPENING_SEARCH(problem) return a solution or failure n༆  Completeness: q༇  YES (no infinite paths) for depth ← 0 to ∞ do result ← DEPTH-LIMITED_SEARCH(problem, depth) if result ≠ cutoff then return result Recall: depth-limited_search returns cutoff when it has r...
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This note was uploaded on 02/10/2014 for the course CS 440 taught by Professor Staff during the Fall '08 term at Colorado State.

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