Sorting Algorithms: Difference between revisions

From NovaOrdis Knowledge Base
Jump to navigation Jump to search
Line 9: Line 9:
The '''sorting problem''' if formally defined as follows: given a sequence of n numbers (a<sub>1</sub>, a<sub>2</sub>, ... a<sub>n</sub>) provided as input, the algorithm must produce as output a permutation (reordering) (a<sup>'</sup><sub>1</sub>, a<sup>'</sup><sub>2</sub>, ... a<sup>'</sup><sub>n</sub>) of the input sequence such that a<sup>'</sup><sub>1</sub> ≤ a<sup>'</sup><sub>2</sub> ≤ ... ≤ a<sup>'</sup><sub>n</sub>. A specific input sequence is called an '''instance''' of the sorting problem.
The '''sorting problem''' if formally defined as follows: given a sequence of n numbers (a<sub>1</sub>, a<sub>2</sub>, ... a<sub>n</sub>) provided as input, the algorithm must produce as output a permutation (reordering) (a<sup>'</sup><sub>1</sub>, a<sup>'</sup><sub>2</sub>, ... a<sup>'</sup><sub>n</sub>) of the input sequence such that a<sup>'</sup><sub>1</sub> ≤ a<sup>'</sup><sub>2</sub> ≤ ... ≤ a<sup>'</sup><sub>n</sub>. A specific input sequence is called an '''instance''' of the sorting problem.


<font color=darkgray>
<span id='Comparison_Sort'></span>'''Comparison sort'''. Cannot do better than n ln n. Proof in a separate article.
* Sorting
 
** Comparison Sort. Comparison sort algorithm class. Know that comparison sort cannot do better than n ln n. Proof in a separate article.
<span id='Non-Comparison_Sort'></span>'''Non-comparison sort'''.
** Non-comparison Sort
 
** Sorting algorithms characteristics (in-place, stability)
Sorting algorithms characteristics:
</font>
* <span id='In-place'></span>'''in-place'''
* <span id='Stability'><span>'''stability'''

Revision as of 03:56, 5 August 2018

Internal

Overview

Many programs use sorting as an intermediate step, and that is why sorting is considered a fundamental operation in computer science.

The sorting problem if formally defined as follows: given a sequence of n numbers (a1, a2, ... an) provided as input, the algorithm must produce as output a permutation (reordering) (a'1, a'2, ... a'n) of the input sequence such that a'1 ≤ a'2 ≤ ... ≤ a'n. A specific input sequence is called an instance of the sorting problem.

Comparison sort. Cannot do better than n ln n. Proof in a separate article.

Non-comparison sort.

Sorting algorithms characteristics:

  • in-place
  • stability