Map Hash Tables and Dictionaries_Part_9

# Map Hash Tables and Dictionaries_Part_9 - Sorted List...

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Last Updated: 06/02/12 10:23 PM CSE 2011 Prof. J. Elder - 41 - Ordered Search Tables Performance: find takes O (log n ) time, using binary search insert takes O ( n ) time since in the worst case we have to shift n items to make room for the new item remove takes O ( n ) time since in the worst case we have to shift n items to compact the items after the removal A search table is effective only for dictionaries of small size or for dictionaries on which searches are the most common operations, while insertions and removals are rarely performed (e.g., credit card authorizations)

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Last Updated: 06/02/12 10:23 PM CSE 2011 Prof. J. Elder - 42 - More on Binary Search
Last Updated: 06/02/12 10:23 PM CSE 2011 Prof. J. Elder - 43 - Define Problem: Binary Search PreConditions Key 25

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Unformatted text preview: Sorted List PostConditions Find key in list (if there). 3 5 6 13 18 21 21 25 36 43 49 51 53 60 72 74 83 88 91 95 3 5 6 13 18 21 21 25 36 43 49 51 53 60 72 74 83 88 91 95 Last Updated: 06/02/12 10:23 PM CSE 2011 Prof. J. Elder - 44 - Define Loop Invariant Maintain a sublist. If the key is contained in the original list, then the key is contained in the sublist. key 25 3 5 6 13 18 21 21 25 36 43 49 51 53 60 72 74 83 88 91 95 Last Updated: 06/02/12 10:23 PM CSE 2011 Prof. J. Elder - 45 - Define Step Cut sublist in half. Determine which half the key would be in. Keep that half. key 25 3 5 6 13 18 21 21 25 36 43 49 51 53 60 72 74 83 88 91 95 If key ≤ mid , then key is in left half. If key > mid , then key is in right half. mid...
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## This note was uploaded on 02/14/2012 for the course CSE 2011Z taught by Professor Elder during the Fall '11 term at York University.

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Map Hash Tables and Dictionaries_Part_9 - Sorted List...

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