Java tutorial
//package com.java2s; /* * USE - UML based specification environment * Copyright (C) 1999-2004 Mark Richters, University of Bremen * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ import java.util.ArrayList; import java.util.List; import java.util.Stack; public class Main { private static <T> void combine(Stack<T> elementStack, List<List<T>> listWithLists, List<List<T>> combinations) { if (elementStack.size() == listWithLists.size()) { combinations.add(new ArrayList<T>(elementStack)); } else { List<T> currentList = listWithLists.get(elementStack.size()); for (T item : currentList) { elementStack.push(item); combine(elementStack, listWithLists, combinations); elementStack.pop(); } } } }