Here you can find the source of crossProduct(Object[] firstArray, Object[]... otherArrays)
| Parameter | Description |
|---|---|
| firstArray | first array that you want to cross product |
| otherArrays | other arrays that you want to cross product |
public static Object[][] crossProduct(Object[] firstArray, Object[]... otherArrays)
//package com.java2s; /**/*from w ww. j a v a 2 s .c o m*/ * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. */ public class Main { /** * Cross product many arrays * @param firstArray first array that you want to cross product * @param otherArrays other arrays that you want to cross product * @return cross product */ public static Object[][] crossProduct(Object[] firstArray, Object[]... otherArrays) { if (otherArrays == null || otherArrays.length == 0) { Object[][] result = new Object[firstArray.length][1]; for (int i = 0; i < firstArray.length; ++i) { result[i][0] = firstArray[i]; } return result; } // computing cross product for the rest of the arrays Object[][] restArray = new Object[otherArrays.length - 1][]; System.arraycopy(otherArrays, 1, restArray, 0, otherArrays.length - 1); Object[][] restCrossProduct = crossProduct(otherArrays[0], restArray); //creating and initializing result array Object[][] result = new Object[firstArray.length * restCrossProduct.length][]; for (int i = 0; i < result.length; ++i) { result[i] = new Object[otherArrays.length + 1]; } //doing the final cross product for (int i = 0; i < firstArray.length; ++i) { for (int j = 0; j < restCrossProduct.length; ++j) { //computing one row of result final int rowIdx = i * restCrossProduct.length + j; result[rowIdx][0] = firstArray[i]; System.arraycopy(restCrossProduct[j], 0, result[rowIdx], 1, otherArrays.length); } } return result; } }