Sorting Algorithms: Difference between revisions
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<span id='Non-Comparison_Sort'></span>'''Non-comparison sort'''. | <span id='Non-Comparison_Sort'></span>'''Non-comparison sort'''. | ||
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Sorting algorithms characteristics: | Sorting algorithms characteristics: | ||
* <span id='In-place'></span>'''in | * <span id='In-place'></span>'''in place''': a sorting algorithm is said to sort the input numbers "in place" if it rearranges the numbers within the input array, while at most a constant number of elements are stored outside the array at any time. | ||
* <span id='Stability'><span>'''stability''' | * <span id='Stability'><span>'''stability''' | ||
Revision as of 21:14, 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: a sorting algorithm is said to sort the input numbers "in place" if it rearranges the numbers within the input array, while at most a constant number of elements are stored outside the array at any time.
- stability