<?xml version="1.0" encoding="UTF-8"?>

<record version="2" id="127">
 <title>sorting problem</title>
 <name>SortingProblem</name>
 <created>2001-10-06 16:20:26</created>
 <modified>2002-05-27 12:44:36</modified>
 <type>Algorithm</type>
 <creator id="6" name="Logan"/>
 <author id="6" name="Logan"/>
 <classification>
	<category scheme="msc" code="68P10"/>
 </classification>
 <related>
	<object name="TotalOrder"/>
	<object name="PartialOrder"/>
	<object name="Relation"/>
	<object name="Heapsort"/>
	<object name="Bubblesort"/>
	<object name="BinarySearch"/>
	<object name="InPlaceSortingAlgorithm"/>
	<object name="InsertionSort"/>
	<object name="LandauNotation"/>
	<object name="Quicksort"/>
	<object name="SelectionSort"/>
 </related>
 <keywords>
	<term>sort</term>
	<term>algorithm</term>
	<term>comparison</term>
 </keywords>
 <preamble>\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{graphicx}
\usepackage{xypic}</preamble>
 <content>Let $\leq$ be a \emph{total ordering} on the set $S$.
Given a sequence of $n$ elements, $x_1, x_2, \dots, x_n \in S$, find a sequence
of distinct indices $1 \leq i_1, i_2, \dots, i_n \leq n$ such that $x_{i_1} \leq x_{i_2} \leq \dots \leq x_{i_n}$.
\\
\\
The sorting problem is a heavily studied area of computer science, and many \emph{sorting algorithms} exist to
solve it.  The most general algorithms depend only upon the relation $\leq$, and are called \emph{comparison-based sorts}.
It can be proved that the lower bound for sorting by any comparison-based sorting algorithm is $\Omega(n\log{n})$.
\\
\\
A few other specialized sort algorithms rely on particular properties of the values of elements in $S$ (such as their structure) in order
to achieve lower time complexity for sorting certain sets of elements.  Examples of such a sorting algorithm are
the \emph{bucket sort} and the \emph{radix sort}.</content>
</record>
