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    copied!<p>Could you maybe share some more of your code and your input data, to get a better understanding of what you are trying to do?</p> <p>This Stack Overflow discussion on <strong>Trie data structures in Java</strong> might be helpful: <a href="https://stackoverflow.com/questions/3806788/trie-data-structures-java?rq=1">Trie data structures - Java</a>. I found the following link (from one of the answers) quite useful: <a href="https://forums.oracle.com/forums/thread.jspa?messageID=8787521" rel="nofollow noreferrer">https://forums.oracle.com/forums/thread.jspa?messageID=8787521</a>.</p> <p>EDIT: with help from <a href="https://forums.oracle.com/forums/thread.jspa?messageID=8787521" rel="nofollow noreferrer">https://forums.oracle.com/forums/thread.jspa?messageID=8787521</a> and <a href="https://stackoverflow.com/questions/3522454/java-tree-data-structure?rq=1">Java tree data-structure?</a>, I created the following code:</p> <pre><code>public Stack&lt;List&lt;Character&gt;&gt; createTreeAndGetAllWords() { // Create the tree. final Tree&lt;Character&gt; rootTree = new Tree&lt;Character&gt;('*'); final Tree&lt;Character&gt; cTree = rootTree.addChild(new Tree&lt;Character&gt;('c')); final Tree&lt;Character&gt; aTree = cTree.addChild(new Tree&lt;Character&gt;('a')); aTree.addChild(new Tree&lt;Character&gt;('r')); aTree.addChild(new Tree&lt;Character&gt;('t')); final Tree&lt;Character&gt; dTree = rootTree.addChild(new Tree&lt;Character&gt;('d')); final Tree&lt;Character&gt; oTree = dTree.addChild(new Tree&lt;Character&gt;('o')); oTree.addChild(new Tree&lt;Character&gt;('g')); // Traverse the tree. return getAllWords(rootTree); } private Stack&lt;List&lt;Character&gt;&gt; getAllWords(final Tree&lt;Character&gt; tree) { final Stack&lt;List&lt;Character&gt;&gt; listStack = new Stack&lt;List&lt;Character&gt;&gt;(); for (final Tree&lt;Character&gt; child : tree.getChildren()) { listStack.push(new ArrayList&lt;Character&gt;()); traverseSubtree(child, listStack); } return listStack; } private void traverseSubtree(final Tree&lt;Character&gt; tree, final Stack&lt;List&lt;Character&gt;&gt; listStack) { final List&lt;Character&gt; currentWord = listStack.pop(); if (tree.hasChildren()) { for (final Tree&lt;Character&gt; child : tree.getChildren()) { final List&lt;Character&gt; extendedWord = new ArrayList&lt;Character&gt;(currentWord); extendedWord.add(tree.getValue()); listStack.push(extendedWord); traverseSubtree(child, listStack); } } else { currentWord.add(tree.getValue()); listStack.push(currentWord); } } public class Tree&lt;T&gt; { private T value; private List&lt;Tree&lt;T&gt;&gt; children; public Tree(T value) { this.value = value; this.children = new ArrayList&lt;Tree&lt;T&gt;&gt;(); } public T getValue() { return value; } public boolean hasChildren() { return children.size() &gt; 0; } public Tree&lt;T&gt; addChild(Tree&lt;T&gt; child) { children.add(child); return child; } public List&lt;Tree&lt;T&gt;&gt; getChildren() { return children; } } </code></pre> <p>When I call createTreeAndGetAllWords, it returns the words I expected as three lists of characters: [c, a, r], [c, a, t] and [d, o, g].</p> <pre><code>for (final List&lt;Character&gt; word : createTreeAndGetAllWords()) { System.out.println("word = " + word); } </code></pre> <p>Cheers, Freek</p>
 

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