1 /* 2 * Copyright (c) 1996, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 /** 27 * Sort: a class that uses the quicksort algorithm to sort an 28 * array of objects. 29 * 30 * @author Sunita Mani 31 */ 32 33 package sun.misc; 34 35 public class Sort { 36 37 private static void swap(Object arr[], int i, int j) { 38 Object tmp; 39 40 tmp = arr[i]; 41 arr[i] = arr[j]; 42 arr[j] = tmp; 43 } 44 45 /** 46 * quicksort the array of objects. 47 * 48 * @param arr[] - an array of objects 49 * @param left - the start index - from where to begin sorting 50 * @param right - the last index. 51 * @param comp - an object that implemnts the Compare interface to resolve thecomparison. 52 */ 53 public static void quicksort(Object arr[], int left, int right, Compare comp) { 54 int i, last; 55 56 if (left >= right) { /* do nothing if array contains fewer than two */ 57 return; /* two elements */ 58 } 59 swap(arr, left, (left+right) / 2); 60 last = left; 61 for (i = left+1; i <= right; i++) { 62 if (comp.doCompare(arr[i], arr[left]) < 0) { 63 swap(arr, ++last, i); 64 } 65 } 66 swap(arr, left, last); 67 quicksort(arr, left, last-1, comp); 68 quicksort(arr, last+1, right, comp); 69 } 70 71 public static void quicksort(Object arr[], Compare comp) { 72 quicksort(arr, 0, arr.length-1, comp); 73 } 74 }