74 lines
2.7 KiB
Java
74 lines
2.7 KiB
Java
/*
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* This file is part of BlueMap, licensed under the MIT License (MIT).
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*
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* Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
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* Copyright (c) contributors
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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package de.bluecolored.bluemap.core.util;
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public class MergeSort {
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/*
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* Adapted from: https://github.com/vigna/fastutil
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*/
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public static void mergeSortInt(final int[] a, final int from, final int to, IntComparator comp, int[] supp) {
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int len = to - from;
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if (len < 16) {
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insertionSortInt(a, from, to, comp);
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return;
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}
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if (supp == null) supp = java.util.Arrays.copyOf(a, to);
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final int mid = (from + to) >>> 1;
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mergeSortInt(supp, from, mid, comp, a);
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mergeSortInt(supp, mid, to, comp, a);
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if (comp.compare(supp[mid - 1], supp[mid]) <= 0) {
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System.arraycopy(supp, from, a, from, len);
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return;
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}
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for (int i = from, p = from, q = mid; i < to; i++) {
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if (q >= to || p < mid && comp.compare(supp[p], supp[q]) <= 0) a[i] = supp[p++];
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else a[i] = supp[q++];
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}
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}
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/*
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* Adapted from: https://github.com/vigna/fastutil
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*/
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private static void insertionSortInt(final int[] a, final int from, final int to, final IntComparator comp) {
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for (int i = from; ++i < to; ) {
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int t = a[i], j = i;
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for (int u = a[j - 1]; comp.compare(t, u) < 0; u = a[--j - 1]) {
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a[j] = u;
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if (from == j - 1) {
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--j;
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break;
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}
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}
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a[j] = t;
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}
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}
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}
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