Sorting Algorithms: Difference between revisions
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The numbers we wish to sort are also known as '''keys'''. | The numbers we wish to sort are also known as '''keys'''. | ||
<span id='Comparison_Sort'></span>A sorting algorithm may compare keys, and in this case it is said to be a '''key comparison algorithm'''. It can be demonstrated that a key comparison algorithm cannot perform better than n lg n. | |||
<font color=darkgray> | <font color=darkgray> | ||
<span id='Non-Comparison_Sort'></span>'''Non-comparison sort'''. | <span id='Non-Comparison_Sort'></span>'''Non-comparison sort'''. | ||
Revision as of 21:07, 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. Although conceptually we are sorting a sequence, the input comes to the sorting function as an array with n elements.
The numbers we wish to sort are also known as keys.
A sorting algorithm may compare keys, and in this case it is said to be a key comparison algorithm. It can be demonstrated that a key comparison algorithm cannot perform better than n lg n.
Non-comparison sort.
Sorting algorithms characteristics:
- in-place
- stability