709 lines
25 KiB
Java
709 lines
25 KiB
Java
/*
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* Copyright 2015 Goldman Sachs.
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* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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import org.openjdk.jmh.annotations.Benchmark;
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import org.openjdk.jmh.annotations.BenchmarkMode;
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import org.openjdk.jmh.annotations.Measurement;
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import org.openjdk.jmh.annotations.Mode;
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import org.openjdk.jmh.annotations.OutputTimeUnit;
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import org.openjdk.jmh.annotations.Param;
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import org.openjdk.jmh.annotations.Scope;
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import org.openjdk.jmh.annotations.Setup;
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import org.openjdk.jmh.annotations.State;
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import org.openjdk.jmh.annotations.Warmup;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.HashSet;
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import java.util.List;
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import java.util.Random;
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import java.util.Set;
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import java.util.concurrent.TimeUnit;
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@State(Scope.Thread)
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@BenchmarkMode(Mode.Throughput)
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@OutputTimeUnit(TimeUnit.SECONDS)
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public class SortingIntBenchmarkTestJMH {
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private static final int QUICKSORT_THRESHOLD = 286;
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private static final int MAX_RUN_COUNT = 67;
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private static final int INSERTION_SORT_THRESHOLD = 47;
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public static final int MAX_VALUE = 1_000_000;
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@Param({"pairFlipZeroPairFlip", "pairFlipOneHundredPairFlip"
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, "zeroHi", "hiZeroLow", "hiFlatLow", "identical",
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"randomDups", "randomNoDups", "sortedReversedSorted", "pairFlip", "endLessThan"})
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public String listType;
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private int[] array;
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private static final int LIST_SIZE = 10_000_000;
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public static final int NUMBER_OF_ITERATIONS = 10;
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@Setup
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public void setUp() {
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Random random = new Random(123456789012345L);
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this.array = new int[LIST_SIZE];
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int threeQuarters = (int) (LIST_SIZE * 0.75);
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if ("zeroHi".equals(this.listType)) {
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for (int i = 0; i < threeQuarters; i++) {
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this.array[i] = 0;
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}
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int k = 1;
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for (int i = threeQuarters; i < LIST_SIZE; i++) {
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this.array[i] = k;
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k++;
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}
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}
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else if ("hiFlatLow".equals(this.listType)) {
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int oneThird = LIST_SIZE / 3;
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for (int i = 0; i < oneThird; i++) {
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this.array[i] = i;
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}
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int twoThirds = oneThird * 2;
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int constant = oneThird - 1;
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for (int i = oneThird; i < twoThirds; i++) {
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this.array[i] = constant;
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}
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for (int i = twoThirds; i < LIST_SIZE; i++) {
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this.array[i] = constant - i + twoThirds;
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}
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}
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else if ("hiZeroLow".equals(this.listType)) {
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int oneThird = LIST_SIZE / 3;
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for (int i = 0; i < oneThird; i++) {
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this.array[i] = i;
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}
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int twoThirds = oneThird * 2;
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for (int i = oneThird; i < twoThirds; i++) {
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this.array[i] = 0;
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}
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for (int i = twoThirds; i < LIST_SIZE; i++) {
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this.array[i] = oneThird - i + twoThirds;
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}
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}
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else if ("identical".equals(this.listType)) {
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for (int i = 0; i < LIST_SIZE; i++) {
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this.array[i] = 0;
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}
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}
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else if ("randomDups".equals(this.listType)) {
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for (int i = 0; i < LIST_SIZE; i++) {
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this.array[i] = random.nextInt(1000);
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}
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}
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else if ("randomNoDups".equals(this.listType)) {
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Set<Integer> set = new HashSet();
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while (set.size() < LIST_SIZE + 1) {
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set.add(random.nextInt());
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}
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List<Integer> list = new ArrayList<>(LIST_SIZE);
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list.addAll(set);
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for (int i = 0; i < LIST_SIZE; i++) {
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this.array[i] = list.get(i);
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}
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}
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else if ("sortedReversedSorted".equals(this.listType)) {
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for (int i = 0; i < LIST_SIZE / 2; i++) {
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this.array[i] = i;
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}
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int num = 0;
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for (int i = LIST_SIZE / 2; i < LIST_SIZE; i++) {
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this.array[i] = LIST_SIZE - num;
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num++;
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}
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}
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else if ("pairFlip".equals(this.listType)) {
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for (int i = 0; i < LIST_SIZE; i++) {
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this.array[i] = i;
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}
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for (int i = 0; i < LIST_SIZE; i += 2) {
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int temp = this.array[i];
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this.array[i] = this.array[i + 1];
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this.array[i + 1] = temp;
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}
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}
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else if ("endLessThan".equals(this.listType)) {
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for (int i = 0; i < LIST_SIZE - 1; i++) {
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this.array[i] = 3;
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}
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this.array[LIST_SIZE - 1] = 1;
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}
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else if ("pairFlipZeroPairFlip".equals(this.listType)) {
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//pairflip
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for (int i = 0; i < 64; i++) {
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this.array[i] = i;
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}
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for (int i = 0; i < 64; i += 2) {
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int temp = this.array[i];
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this.array[i] = this.array[i + 1];
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this.array[i + 1] = temp;
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}
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//zero
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for (int i = 64; i < this.array.length - 64; i++) {
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this.array[i] = 0;
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}
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//pairflip
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for (int i = this.array.length - 64; i < this.array.length; i++) {
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this.array[i] = i;
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}
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for (int i = this.array.length - 64; i < this.array.length; i += 2) {
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int temp = this.array[i];
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this.array[i] = this.array[i + 1];
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this.array[i + 1] = temp;
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}
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}
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else if ("pairFlipOneHundredPairFlip".equals(this.listType)) {
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//10, 5
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for (int i = 0; i < 64; i++) {
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if (i % 2 == 0) {
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this.array[i] = 10;
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}
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else {
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this.array[i] = 5;
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}
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}
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//100
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for (int i = 64; i < this.array.length - 64; i++) {
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this.array[i] = 100;
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}
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//10, 5
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for (int i = this.array.length - 64; i < this.array.length; i++) {
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if (i % 2 == 0) {
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this.array[i] = 10;
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}
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else {
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this.array[i] = 5;
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}
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}
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}
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}
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@Warmup(iterations = 20)
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@Measurement(iterations = 10)
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@Benchmark
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public void sortNewWay() {
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for (int i = 0; i < NUMBER_OF_ITERATIONS; i++) {
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SortingIntTestJMH.sort(this.array, 0, this.array.length - 1, null, 0, 0);
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}
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}
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@Warmup(iterations = 20)
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@Measurement(iterations = 10)
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@Benchmark
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public void sortCurrentWay() {
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for (int i = 0; i < NUMBER_OF_ITERATIONS; i++) {
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Arrays.sort(this.array);
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}
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}
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static void sort(int[] a, int left, int right,
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int[] work, int workBase, int workLen) {
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// Use Quicksort on small arrays
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if (right - left < QUICKSORT_THRESHOLD) {
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SortingIntTestJMH.sort(a, left, right, true);
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return;
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}
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/*
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* Index run[i] is the start of i-th run
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* (ascending or descending sequence).
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*/
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int[] run = new int[MAX_RUN_COUNT + 1];
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int count = 0;
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run[0] = left;
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// Check if the array is nearly sorted
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for (int k = left; k < right; run[count] = k) {
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while (k < right && a[k] == a[k + 1])
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k++;
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if (k == right) break;
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if (a[k] < a[k + 1]) { // ascending
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while (++k <= right && a[k - 1] <= a[k]) ;
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}
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else if (a[k] > a[k + 1]) { // descending
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while (++k <= right && a[k - 1] >= a[k]) ;
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for (int lo = run[count] - 1, hi = k; ++lo < --hi; ) {
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int t = a[lo];
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a[lo] = a[hi];
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a[hi] = t;
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}
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}
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if (run[count] > left && a[run[count]] >= a[run[count] - 1]) {
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count--;
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}
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/*
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* The array is not highly structured,
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* use Quicksort instead of merge sort.
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*/
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if (++count == MAX_RUN_COUNT) {
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sort(a, left, right, true);
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return;
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}
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}
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// Check special cases
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// Implementation note: variable "right" is increased by 1.
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if (run[count] == right++) {
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run[++count] = right;
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}
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if (count <= 1) { // The array is already sorted
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return;
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}
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// Determine alternation base for merge
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byte odd = 0;
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for (int n = 1; (n <<= 1) < count; odd ^= 1) {
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}
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// Use or create temporary array b for merging
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int[] b; // temp array; alternates with a
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int ao, bo; // array offsets from 'left'
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int blen = right - left; // space needed for b
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if (work == null || workLen < blen || workBase + blen > work.length) {
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work = new int[blen];
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workBase = 0;
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}
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if (odd == 0) {
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System.arraycopy(a, left, work, workBase, blen);
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b = a;
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bo = 0;
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a = work;
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ao = workBase - left;
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}
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else {
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b = work;
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ao = 0;
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bo = workBase - left;
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}
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// Merging
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for (int last; count > 1; count = last) {
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for (int k = (last = 0) + 2; k <= count; k += 2) {
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int hi = run[k], mi = run[k - 1];
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for (int i = run[k - 2], p = i, q = mi; i < hi; ++i) {
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if (q >= hi || p < mi && a[p + ao] <= a[q + ao]) {
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b[i + bo] = a[p++ + ao];
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}
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else {
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b[i + bo] = a[q++ + ao];
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}
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}
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run[++last] = hi;
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}
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if ((count & 1) != 0) {
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for (int i = right, lo = run[count - 1]; --i >= lo;
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b[i + bo] = a[i + ao]
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) {
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}
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run[++last] = right;
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}
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int[] t = a;
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a = b;
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b = t;
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int o = ao;
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ao = bo;
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bo = o;
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}
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}
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private static void sort(int[] a, int left, int right, boolean leftmost) {
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int length = right - left + 1;
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// Use insertion sort on tiny arrays
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if (length < INSERTION_SORT_THRESHOLD) {
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if (leftmost) {
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/*
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* Traditional (without sentinel) insertion sort,
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* optimized for server VM, is used in case of
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* the leftmost part.
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*/
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for (int i = left, j = i; i < right; j = ++i) {
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int ai = a[i + 1];
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while (ai < a[j]) {
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a[j + 1] = a[j];
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if (j-- == left) {
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break;
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}
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}
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a[j + 1] = ai;
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}
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}
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else {
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/*
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* Skip the longest ascending sequence.
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*/
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do {
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if (left >= right) {
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return;
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}
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}
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while (a[++left] >= a[left - 1]);
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/*
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* Every element from adjoining part plays the role
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* of sentinel, therefore this allows us to avoid the
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* left range check on each iteration. Moreover, we use
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* the more optimized algorithm, so called pair insertion
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* sort, which is faster (in the context of Quicksort)
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* than traditional implementation of insertion sort.
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*/
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for (int k = left; ++left <= right; k = ++left) {
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int a1 = a[k], a2 = a[left];
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if (a1 < a2) {
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a2 = a1;
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a1 = a[left];
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}
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while (a1 < a[--k]) {
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a[k + 2] = a[k];
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}
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a[++k + 1] = a1;
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while (a2 < a[--k]) {
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a[k + 1] = a[k];
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}
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a[k + 1] = a2;
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}
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int last = a[right];
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while (last < a[--right]) {
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a[right + 1] = a[right];
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}
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a[right + 1] = last;
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}
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return;
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}
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// Inexpensive approximation of length / 7
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int seventh = (length >> 3) + (length >> 6) + 1;
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/*
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* Sort five evenly spaced elements around (and including) the
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* center element in the range. These elements will be used for
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* pivot selection as described below. The choice for spacing
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* these elements was empirically determined to work well on
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* a wide variety of inputs.
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*/
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int e3 = (left + right) >>> 1; // The midpoint
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int e2 = e3 - seventh;
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int e1 = e2 - seventh;
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int e4 = e3 + seventh;
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int e5 = e4 + seventh;
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// Sort these elements using insertion sort
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if (a[e2] < a[e1]) {
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int t = a[e2];
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a[e2] = a[e1];
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a[e1] = t;
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}
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if (a[e3] < a[e2]) {
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int t = a[e3];
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a[e3] = a[e2];
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a[e2] = t;
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if (t < a[e1]) {
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a[e2] = a[e1];
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a[e1] = t;
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}
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}
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if (a[e4] < a[e3]) {
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int t = a[e4];
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a[e4] = a[e3];
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a[e3] = t;
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if (t < a[e2]) {
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a[e3] = a[e2];
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a[e2] = t;
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if (t < a[e1]) {
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a[e2] = a[e1];
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a[e1] = t;
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}
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}
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}
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if (a[e5] < a[e4]) {
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int t = a[e5];
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a[e5] = a[e4];
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a[e4] = t;
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if (t < a[e3]) {
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a[e4] = a[e3];
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a[e3] = t;
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if (t < a[e2]) {
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a[e3] = a[e2];
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a[e2] = t;
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if (t < a[e1]) {
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a[e2] = a[e1];
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a[e1] = t;
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}
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}
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}
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}
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// Pointers
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int less = left; // The index of the first element of center part
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int great = right; // The index before the first element of right part
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if (a[e1] != a[e2] && a[e2] != a[e3] && a[e3] != a[e4] && a[e4] != a[e5]) {
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/*
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* Use the second and fourth of the five sorted elements as pivots.
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* These values are inexpensive approximations of the first and
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* second terciles of the array. Note that pivot1 <= pivot2.
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*/
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int pivot1 = a[e2];
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int pivot2 = a[e4];
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/*
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* The first and the last elements to be sorted are moved to the
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* locations formerly occupied by the pivots. When partitioning
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* is complete, the pivots are swapped back into their final
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* positions, and excluded from subsequent sorting.
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*/
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a[e2] = a[left];
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a[e4] = a[right];
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/*
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* Skip elements, which are less or greater than pivot values.
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*/
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while (a[++less] < pivot1) {
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}
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while (a[--great] > pivot2) {
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}
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/*
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* Partitioning:
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*
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* left part center part right part
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* +--------------------------------------------------------------+
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* | < pivot1 | pivot1 <= && <= pivot2 | ? | > pivot2 |
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* +--------------------------------------------------------------+
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* ^ ^ ^
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* | | |
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* less k great
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*
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* Invariants:
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*
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* all in (left, less) < pivot1
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* pivot1 <= all in [less, k) <= pivot2
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* all in (great, right) > pivot2
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*
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* Pointer k is the first index of ?-part.
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*/
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outer:
|
|
for (int k = less - 1; ++k <= great; ) {
|
|
int ak = a[k];
|
|
if (ak < pivot1) { // Move a[k] to left part
|
|
a[k] = a[less];
|
|
/*
|
|
* Here and below we use "a[i] = b; i++;" instead
|
|
* of "a[i++] = b;" due to performance issue.
|
|
*/
|
|
a[less] = ak;
|
|
++less;
|
|
}
|
|
else if (ak > pivot2) { // Move a[k] to right part
|
|
while (a[great] > pivot2) {
|
|
if (great-- == k) {
|
|
break outer;
|
|
}
|
|
}
|
|
if (a[great] < pivot1) { // a[great] <= pivot2
|
|
a[k] = a[less];
|
|
a[less] = a[great];
|
|
++less;
|
|
}
|
|
else { // pivot1 <= a[great] <= pivot2
|
|
a[k] = a[great];
|
|
}
|
|
/*
|
|
* Here and below we use "a[i] = b; i--;" instead
|
|
* of "a[i--] = b;" due to performance issue.
|
|
*/
|
|
a[great] = ak;
|
|
--great;
|
|
}
|
|
}
|
|
|
|
// Swap pivots into their final positions
|
|
a[left] = a[less - 1];
|
|
a[less - 1] = pivot1;
|
|
a[right] = a[great + 1];
|
|
a[great + 1] = pivot2;
|
|
|
|
// Sort left and right parts recursively, excluding known pivots
|
|
SortingIntTestJMH.sort(a, left, less - 2, leftmost);
|
|
SortingIntTestJMH.sort(a, great + 2, right, false);
|
|
|
|
/*
|
|
* If center part is too large (comprises > 4/7 of the array),
|
|
* swap internal pivot values to ends.
|
|
*/
|
|
if (less < e1 && e5 < great) {
|
|
/*
|
|
* Skip elements, which are equal to pivot values.
|
|
*/
|
|
while (a[less] == pivot1) {
|
|
++less;
|
|
}
|
|
|
|
while (a[great] == pivot2) {
|
|
--great;
|
|
}
|
|
|
|
/*
|
|
* Partitioning:
|
|
*
|
|
* left part center part right part
|
|
* +----------------------------------------------------------+
|
|
* | == pivot1 | pivot1 < && < pivot2 | ? | == pivot2 |
|
|
* +----------------------------------------------------------+
|
|
* ^ ^ ^
|
|
* | | |
|
|
* less k great
|
|
*
|
|
* Invariants:
|
|
*
|
|
* all in (*, less) == pivot1
|
|
* pivot1 < all in [less, k) < pivot2
|
|
* all in (great, *) == pivot2
|
|
*
|
|
* Pointer k is the first index of ?-part.
|
|
*/
|
|
outer:
|
|
for (int k = less - 1; ++k <= great; ) {
|
|
int ak = a[k];
|
|
if (ak == pivot1) { // Move a[k] to left part
|
|
a[k] = a[less];
|
|
a[less] = ak;
|
|
++less;
|
|
}
|
|
else if (ak == pivot2) { // Move a[k] to right part
|
|
while (a[great] == pivot2) {
|
|
if (great-- == k) {
|
|
break outer;
|
|
}
|
|
}
|
|
if (a[great] == pivot1) { // a[great] < pivot2
|
|
a[k] = a[less];
|
|
/*
|
|
* Even though a[great] equals to pivot1, the
|
|
* assignment a[less] = pivot1 may be incorrect,
|
|
* if a[great] and pivot1 are floating-point zeros
|
|
* of different signs. Therefore in float and
|
|
* double sorting methods we have to use more
|
|
* accurate assignment a[less] = a[great].
|
|
*/
|
|
a[less] = pivot1;
|
|
++less;
|
|
}
|
|
else { // pivot1 < a[great] < pivot2
|
|
a[k] = a[great];
|
|
}
|
|
a[great] = ak;
|
|
--great;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Sort center part recursively
|
|
SortingIntTestJMH.sort(a, less, great, false);
|
|
}
|
|
else { // Partitioning with one pivot
|
|
/*
|
|
* Use the third of the five sorted elements as pivot.
|
|
* This value is inexpensive approximation of the median.
|
|
*/
|
|
int pivot = a[e3];
|
|
|
|
/*
|
|
* Partitioning degenerates to the traditional 3-way
|
|
* (or "Dutch National Flag") schema:
|
|
*
|
|
* left part center part right part
|
|
* +-------------------------------------------------+
|
|
* | < pivot | == pivot | ? | > pivot |
|
|
* +-------------------------------------------------+
|
|
* ^ ^ ^
|
|
* | | |
|
|
* less k great
|
|
*
|
|
* Invariants:
|
|
*
|
|
* all in (left, less) < pivot
|
|
* all in [less, k) == pivot
|
|
* all in (great, right) > pivot
|
|
*
|
|
* Pointer k is the first index of ?-part.
|
|
*/
|
|
for (int k = less; k <= great; ++k) {
|
|
if (a[k] == pivot) {
|
|
continue;
|
|
}
|
|
int ak = a[k];
|
|
if (ak < pivot) { // Move a[k] to left part
|
|
a[k] = a[less];
|
|
a[less] = ak;
|
|
++less;
|
|
}
|
|
else { // a[k] > pivot - Move a[k] to right part
|
|
while (a[great] > pivot) {
|
|
--great;
|
|
}
|
|
if (a[great] < pivot) { // a[great] <= pivot
|
|
a[k] = a[less];
|
|
a[less] = a[great];
|
|
++less;
|
|
}
|
|
else { // a[great] == pivot
|
|
/*
|
|
* Even though a[great] equals to pivot, the
|
|
* assignment a[k] = pivot may be incorrect,
|
|
* if a[great] and pivot are floating-point
|
|
* zeros of different signs. Therefore in float
|
|
* and double sorting methods we have to use
|
|
* more accurate assignment a[k] = a[great].
|
|
*/
|
|
a[k] = pivot;
|
|
}
|
|
a[great] = ak;
|
|
--great;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Sort left and right parts recursively.
|
|
* All elements from center part are equal
|
|
* and, therefore, already sorted.
|
|
*/
|
|
SortingIntTestJMH.sort(a, left, less - 1, leftmost);
|
|
SortingIntTestJMH.sort(a, great + 1, right, false);
|
|
}
|
|
}
|
|
|
|
private static void swap(int[] arr, int i, int j) {
|
|
int tmp = arr[i];
|
|
arr[i] = arr[j];
|
|
arr[j] = tmp;
|
|
}
|
|
}
|