1. Sorting algorithms

2. Outline In this lesson, we will: Describe sorting algorithms
Given an overview of existing algorithms
Describe the sorting algorithms we will learn

3. Sorting Given an array that has arbitrary entries,
int array[10]{82, 25, 32, 85, 16, 36, 40, 4, 28, 7};
the entries are not in order
Can we reorder the entries in the array to produce the sorted array ?
Such an algorithm is described as a sorting algorithm 1 2 3 4 5 6 7 8 9 82 25 42 85 16 32 28 1 2 3 4 5 6 7 8 9 16 25 28 32 42 82 85

4. Sorting algorithms There are many different sorting algorithms
selection sort insertion sort shell sort
comb sort gnome sort heap sort
merge sort quick sort bucket sort
radix sort cube sort block sort
There are even humorous ones:
bozo sort bogo sort stooge sort
Some sorting algorithms are worse than others:
bubble sort
If you have ever learned bubble sort, please forget it…
Even Barack Obama knows not to use bubble sort

5. Sorting algorithms We will look at three algorithms:
Selection sort
Insertion sort
Bucket sort
Each of these algorithms has something to commend it, but each also has issues
There is no perfect one-size-fits-all sorting algorithm
Each algorithm has its own benefits and drawbacks
Except bubble sort: its only redeeming feature is a memorable name
In a final subsequent set of lectures, we will look at merge sort

6. Sorting algorithms
The function declaration of each sorting algorithm will be similar:
template <typename T>
void algorithm_name( T array[],
std::size_t const capacity );
Only the capacity is declared constant—it should not change
The entries of the array will be changed by the algorithm

7. Summary Following this lesson, you now
Understand the definition of a sorting algorithm
Know the signature that these algorithms will use

8. References
[1] Wikipedia [2] nist Dictionary of Algorithms and Data Structures

9. Colophon
These slides were prepared using the Georgia typeface. Mathematical equations use Times New Roman, and source code is presented using Consolas. The photographs of lilacs in bloom appearing on the title slide and accenting the top of each other slide were taken at the Royal Botanical Gardens on May 27, 2018 by Douglas Wilhelm Harder. Please see for more information.

10. Disclaimer
These slides are provided for the ece 150 Fundamentals of Programming course taught at the University of Waterloo. The material in it reflects the authors’ best judgment in light of the information available to them at the time of preparation. Any reliance on these course slides by any party for any other purpose are the responsibility of such parties. The authors accept no responsibility for damages, if any, suffered by any party as a result of decisions made or actions based on these course slides for any other purpose than that for which it was intended.