1. Sorting Chapter 12 Objectives Upon completion you will be able to:
Understand the basic concepts of internal and external sorts
Discuss the relative efficiency of different sorts
Recognize and discuss selection, insertion and exchange sorts
Discuss the design and operation of external sorts
Recognize natural, balanced, and polyphase merge sorts
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2. 12-1 Sort Concepts Sort Order Sort Stability Sort Efficiency Passes
Sorts arrange data according to their value. In this chapter, we discuss both internal and external sorts. We divide internal sorts into three categories-insertion, selection, and exchange-and discuss two different sorts in each classification. At the end of the chapter we discuss natural, balanced, and polyphase external sorts. We begin with a discussion of several sort concepts in Section 12.1.
Sort Order
Sort Stability
Sort Efficiency
Passes
Sorts and ADTs
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3. Sort concepts
Sort
The process through which data are arranged according to their values.
Sorting is one of the most common data-processing applications.
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4. Sort classifications
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5. Sort order
The sort order identifies the sequence of sorted data, ascending or descending.
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6. Sort order
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7. Sort stability
Sort stability is an attribute of a sort, indicating that data with equal keys maintain their relative input order in the output.
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8. Sort efficiency
Sort efficiency is a measure of the relative efficiency of a sort.
Quick sort (best)
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9. Passes During the sorting process, the data traversed many times.
Each traversal of the data is referred as a sort pass.
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10. 12-2 Selection Sorts Straight Selection Sort Heap Sort
In each pass of the selection sort, the smallest element is selected from the unsorted sublist and exchanged with the element at the beginning of the unsorted list. We discuss two classic selection sorts, straight selection and heap sort.
Straight Selection Sort
Heap Sort
Selection Sort Efficiency
Selection Sort Implementation
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11. Selection sorts
Selection sorts are among the most intuitive of all sorts.
Straight Selection Sort
Heap sort
In each pass of the selection sort, the smallest element is selected from the unsorted sublist and exchanged with the element at the beginning of the unsorted list.
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12. Straight selection sort
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13. Selection sort
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14. Selection sort algorithm
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15. Selection sort algorithm
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16. Heap sort
The heap sort is an improved version of the selection sort in which the largest element (the root) is selected and exchanged with the last element in the unsorted list.
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18. Heap sort exchange process
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19. Heap sort process
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21. Selection sort efficiency
The straight selection sort efficiency is O(n2).
The heap sort efficiency is O(n log n)
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22. Selection sort implementation
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24. Heap sort implementation
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30. 12-3 Insertion Sorts Straight Insertion Sort Shell Sort
In each pass of an insertion sort, one or more pieces of data are inserted into their correct location in an ordered list.
In this section we study two insertion sorts: the straight insertion sort and the shell sort.
Straight Insertion Sort
Shell Sort
Insertion Sort Efficiency
Insertion Sort Implementation
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31. Straight insertion sort
The list at any moment is divided into sorted and unsorted sublists.
In each pass the first element of the unsorted sublist is inserted into the sorted sublist.
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32. Straight insertion sort
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33. Straight insertion sort example
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35. Shell sort
The shell sort is an improved version of the straight insertion sort in which diminishing partitions are used to sorted the data.
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36. Segmented array N = 10 Increment (K) = 3
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37. Diminishing increments in shell sort
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38. Diminishing increments in shell sort
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39. Diminishing increments in shell sort
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40. Diminishing increments in shell sort
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43. Straight insertion sort efficiency
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44. Shell sort efficiency O(N1.25)
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45. Comparison of insertion and selection sorts
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49. 12-4 Exchange Sorts Bubble Sort Quick Sort Exchange Sort Efficiency
Sort Summary
Exchange Sort Implementation
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50. Exchanged sort
In exchange sorts we exchange elements that are out of order until the entire list is sorted.
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51. Bubble sort
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52. Bubble sort concept
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53. Bubble sort example
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54. Data Structures: A Pseudocode Approach with C, Second Edition

55. Quick sort
Quick sort is an exchange sort in which a pivot key is placed in its correct position in the array while rearranging other elements widely dispersed across the list.
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56. Quick sort Each iteration of the quick sort
selects an element, known as pivot, and
Divides the list into three groups
A partition of elements < the pivot’s key
The pivot element that is placed in its ultimately correct location in the list
A partition of elements ≧ the pivot’s key
The sorting then continues by quick sorting the left partition followed by quick sorting the right partition.
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57. Quick sort partitions
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58. Quick sort algorithm Straight insertion module
Determine median of three
Quick sort algorithm
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61. Quick sort pivot
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62. Quick sort operation
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65. Exchange sort efficiency
The bubble sort efficiency is O(n2).
The quick sort efficiency is O(n log n).
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66. Sort comparisons
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76. 12-5 External Sorts Merging Ordered Files Merging Unordered Files
In external sorting portions of the data may be stored in secondary memory during the sorting process. Included in this section is a discussion of file merging and three external sort approaches-natural, balanced, and polyphase.
Merging Ordered Files
Merging Unordered Files
The Sorting Process
Sort Phase Revisited
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85. 12-6 Quick Sort Efficiency
We revisit the general approach to analyzing algorithm efficiency with an in-depth discussion of the quick sort's efficiency.
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