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Jenetics - Java Genetic Algorithm Library

There is a newer version: 3.6.0

/*
 * Java Genetic Algorithm Library (jenetics-3.1.0).
 * Copyright (c) 2007-2015 Franz Wilhelmstötter
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Author:
 *    Franz Wilhelmstötter ([email protected])
 */
package org.jenetics.internal.util;

import java.util.Random;

import org.jenetics.util.RandomRegistry;

/**
 * Helper class which contains array helper methods.
 *
 * @author Franz Wilhelmstötter
 * @since 3.0
 * @version 3.0
 */
public final class array {
	private array() {require.noInstance();}

	public static void swap(final int[] array, final int i, final int j) {
		final int temp = array[i];
		array[i] = array[j];
		array[j] = temp;
	}

	public static void swap(final double[] array, final int i, final int j) {
		final double temp = array[i];
		array[i] = array[j];
		array[j] = temp;
	}

	public static int[] revert(final int[] array) {
		for (int i = 0, j = array.length - 1; i < j; ++i, --j) {
			swap(array, i, j);
		}

		return array;
	}

	public static double[] revert(final double[] array) {
		for (int i = 0, j = array.length - 1; i < j; ++i, --j) {
			swap(array, i, j);
		}

		return array;
	}

	public static void shuffle(final double[] array, final Random random) {
		for (int i = array.length; --i >=0;) {
			swap(array, i, random.nextInt(array.length));
		}
	}

	public static void shuffle(final double[] array) {
		shuffle(array, RandomRegistry.getRandom());
	}
}