edu.princeton.cs.algs4

Class Quick

java.lang.Object

edu.princeton.cs.algs4.Quick

public class Quick
extends java.lang.Object

The Quick class provides static methods for sorting an array and selecting the ith smallest element in an array using quicksort.

For additional documentation, see Section 2.3 of Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.

Method Summary

Modifier and Type	Method and Description
static void	main(java.lang.String[] args) Reads in a sequence of strings from standard input; quicksorts them; and prints them to standard output in ascending order.
static java.lang.Comparable	select(java.lang.Comparable[] a, int k) Rearranges the array so that a[k] contains the kth smallest key; a[0] through a[k-1] are less than (or equal to) a[k]; and a[k+1] through a[n-1] are greater than (or equal to) a[k].
static void	sort(java.lang.Comparable[] a) Rearranges the array in ascending order, using the natural order.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

sort

public static void sort(java.lang.Comparable[] a)

Rearranges the array in ascending order, using the natural order.

Parameters:

a - the array to be sorted

select

public static java.lang.Comparable select(java.lang.Comparable[] a,
                                          int k)

Rearranges the array so that a[k] contains the kth smallest key; a[0] through a[k-1] are less than (or equal to) a[k]; and a[k+1] through a[n-1] are greater than (or equal to) a[k].

Parameters:

a - the array

k - the rank of the key

Returns:

the key of rank k

Throws:

java.lang.IllegalArgumentException - unless 0 <= k < a.length

main

public static void main(java.lang.String[] args)

Reads in a sequence of strings from standard input; quicksorts them; and prints them to standard output in ascending order. Shuffles the array and then prints the strings again to standard output, but this time, using the select method.

Parameters:

args - the command-line arguments