1. MSIS 655 Advanced Business Applications Programming
Week 13
Searching and Sorting (cont.)
In this chapter you will learn:
To sort arrays using the recursive merge sort algorithm.
To determine the efficiency of merge sort algorithms.
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2. Merge Sort
Splits array into two approximately equal sized subarrays, sorts each subarray, then merges the subarrays
The following implementation is recursive
Base case is a one-element array which cannot be unsorted
Recursion step splits an array into two pieces, sorts each piece, then merges the sorted pieces
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7. Efficiency of Merge Sort
Far more efficient than selection sort or insertion sort
Last merge requires n – 1 comparisons to merge entire array
Each lower level has twice as many calls to method merge, with each call operating on an array half the size which results in O(n) total comparisons
There will be O(log n) levels
Results in O(n log n)
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8. Lab activities (Week 13)
Exercise (pp. 816) 16.10
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