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Added byte[] and long[] variants of shuffle().

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git-svn-id: https://samskivert.googlecode.com/svn/trunk@762 6335cc39-0255-0410-8fd6-9bcaacd3b74c
This commit is contained in:
shaper
2002-05-28 22:32:14 +00:00
parent eb88c5a4ef
commit 9c33c3da0f
1 changed files with 59 additions and 2 deletions
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projects/samskivert/src/java/com/samskivert/util/ArrayUtil.java
+59 -2
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@@ -1,5 +1,5 @@
//
// $Id: ArrayUtil.java,v 1.2 2001/12/14 19:07:47 shaper Exp $
// $Id: ArrayUtil.java,v 1.3 2002/05/28 22:32:14 shaper Exp $
//
// samskivert library - useful routines for java programs
// Copyright (C) 2001 Walter Korman
@@ -27,6 +27,34 @@ import java.util.Random;
*/
public class ArrayUtil
{
/**
* Shuffles the elements in the given array into a random sequence.
*
* @param values the array to shuffle.
*/
public static void shuffle (byte[] values)
{
shuffle(values, 0, values.length);
}
/**
* Shuffles a subset of elements within the specified array into a
* random sequence.
*
* @param values the array containing elements to shuffle.
* @param offset the index at which to start shuffling elements.
* @param length the number of elements to shuffle.
*/
public static void shuffle (byte[] values, int offset, int length)
{
for (int ii = (offset + length); ii > (offset + 1); ii--) {
byte temp = values[ii - 1];
int idx = _rnd.nextInt(ii);
values[ii - 1] = values[idx];
values[idx] = temp;
}
}
/**
* Shuffles the elements in the given array into a random sequence.
*
@@ -38,7 +66,8 @@ public class ArrayUtil
}
/**
* Shuffles a subset of elements within the specified array.
* Shuffles a subset of elements within the specified array into a
* random sequence.
*
* @param values the array containing elements to shuffle.
* @param offset the index at which to start shuffling elements.
@@ -54,6 +83,34 @@ public class ArrayUtil
}
}
/**
* Shuffles the elements in the given array into a random sequence.
*
* @param values the array to shuffle.
*/
public static void shuffle (long[] values)
{
shuffle(values, 0, values.length);
}
/**
* Shuffles a subset of elements within the specified array into a
* random sequence.
*
* @param values the array containing elements to shuffle.
* @param offset the index at which to start shuffling elements.
* @param length the number of elements to shuffle.
*/
public static void shuffle (long[] values, int offset, int length)
{
for (int ii = (offset + length); ii > (offset + 1); ii--) {
long temp = values[ii - 1];
int idx = _rnd.nextInt(ii);
values[ii - 1] = values[idx];
values[idx] = temp;
}
}
/** The random object used when shuffling an array. */
protected static Random _rnd = new Random();
}