/**
* Copyright (c) 2009 Juwi MacMillan Group GmbH
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.tizzit.util;
/**
*
* @author <a href="sascha.kulawik@juwimm.com">Sascha-Matthias Kulawik</a>
* @version $Id$
*/
public final class ArraySorter {
private ArraySorter() {
}
/*
** Sort in the same array
*/
public static void sort(Object[] a, Comparer comparer) {
sort(a, null, 0, a.length - 1, true, comparer);
}
/*
** Sort a and b, using a as the reference
*/
public static void sort(Object[] a, Object[] b, int from, int to, boolean ascending, Comparer comparer) {
// No sort
if (a == null || a.length < 2) { return; }
// sort using Quicksort
int i = from, j = to;
Object center = a[(from + to) / 2];
do {
if (ascending) {
while ((i < to) && (comparer.compare(center, a[i]) > 0)) {
i++;
}
while ((j > from) && (comparer.compare(center, a[j]) < 0)) {
j--;
}
} else {
// Decending sort
while ((i < to) && (comparer.compare(center, a[i]) < 0)) {
i++;
}
while ((j > from) && (comparer.compare(center, a[j]) > 0)) {
j--;
}
}
if (i < j) {
// Swap elements
Object temp = a[i];
a[i] = a[j];
a[j] = temp;
// Swap in b array if needed
if (b != null) {
temp = b[i];
b[i] = b[j];
b[j] = temp;
}
}
if (i <= j) {
i++;
j--;
}
} while (i <= j);
// Sort the rest
if (from < j) {
sort(a, b, from, j, ascending, comparer);
}
if (i < to) {
sort(a, b, i, to, ascending, comparer);
}
}
}