Java Array Invert invertMapping(int[] mapping)

Description

Inverts the mapping into the source array.

License

BSD License

Declaration

public static void invertMapping(int[] mapping) 

Method Source Code

//package com.java2s;
/*/*from www .  j av  a2s .  c om*/
 * =============================================================================
 * Simplified BSD License, see http://www.opensource.org/licenses/
 * -----------------------------------------------------------------------------
 * Copyright (c) 2008-2009, Marco Terzer, Zurich, Switzerland
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * 
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 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright 
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 *     * Neither the name of the Swiss Federal Institute of Technology Zurich 
 *       nor the names of its contributors may be used to endorse or promote 
 *       products derived from this software without specific prior written 
 *       permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 * =============================================================================
 */

public class Main {
    /**
     * Inverts the mapping into the source array. In the resulting mapping,
     * inv[orig[i]] = i
     */
    public static void invertMapping(int[] mapping) {
        invertMapping(mapping, mapping);
    }

    /**
     * Inverts the mapping into the source array. In the resulting mapping,
     * inv[orig[i]] = i. The method works also if orig and inv is the same 
     * array.
     */
    public static void invertMapping(int[] orig, final int[] inv) {
        if (inv == orig) {
            orig = clone(orig);
        }
        for (int ii = 0; ii < orig.length; ii++) {
            inv[orig[ii]] = ii;
        }
    }

    /**
     * Returns a clone of the given mapping. This method is faster than the 
     * clone method of an array
     */
    public static int[] clone(final int[] original) {
        final int[] clone = new int[original.length];
        System.arraycopy(original, 0, clone, 0, original.length);
        return clone;
    }
}

Related

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2. invertI(long[] v)
3. invertirTabla2(int[] tabla)
4. invertList(int[] pos)
5. invertMap(int[] map)
6. invertOrder(double[] values)
7. invertOrientation(int[] face)
8. invertValues(double[] vector)
9. InvertVector(int v[])