Java List Merge mergeBandY(List<T> A, int z, int y, int yn)

Description

Auxilliary method required for merging two consecutive sorted lists in place.

License

Open Source License

Declaration

private static <T extends Comparable<? super T>> void mergeBandY(List<T> A, int z, int y, int yn)

Method Source Code

//package com.java2s;
/**/*from  w  ww.  j a  v a2  s  .  co  m*/
 * Java Modular Image Synthesis Toolkit (JMIST)
 * Copyright (C) 2008-2013 Bradley W. Kimmel
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

import java.util.Collections;
import java.util.List;

public class Main {
    /**
     * Auxilliary method required for merging two consecutive sorted lists in
     * place.
     *
     * <p>This implementation is based on:</p>
     *
     * <p>J. Chen, "<a href="http://dx.doi.org/10.1016/j.ipl.2005.11.018">A
     * simple algorithm for in-place merging</a>", Information Processing
     * Letters 98:34-40, 2006.</p>.
     *
     * This method is a direct transcription of Fig. 5.
     */
    private static <T extends Comparable<? super T>> void mergeBandY(List<T> A, int z, int y, int yn) {
        while (z < y && y <= yn) {
            int j = z + indexOfMin(A.subList(z, y));
            if (A.get(j).compareTo(A.get(y)) <= 0) {
                Collections.swap(A, z, j);
            } else {
                Collections.swap(A, z, y);
                y++;
            }
            z++;
        }
        if (z < y) {
            Collections.sort(A.subList(z, yn + 1));
        }
    }

    /**
     * Finds the first index of a minimal element in a list.
     * @param list The <code>List</code> to search.
     * @return The first index of a minimal element in the list.
     */
    public static <T extends Comparable<? super T>> int indexOfMin(List<T> list) {
        T min = list.get(0);
        int index = 0;
        for (int i = 0, n = list.size(); i < n; i++) {
            T value = list.get(i);
            if (value.compareTo(min) < 0) {
                min = value;
                index = i;
            }
        }
        return index;
    }
}

Java List Merge mergeBandY(List A, int z, int y, int yn)

Description

License

Declaration

Method Source Code

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