gistfile1.java

    TreeItem findStack2(TreeItem root, Object obj) {
        maxStackSize = 0;
        Deque<Iterator<TreeItem>> stack = new ArrayDeque<Iterator<TreeItem>>();
        stack.push(Collections.singletonList(root).iterator());
        while (!stack.isEmpty()) {
            Iterator<TreeItem> it = stack.peek();
            if (it.hasNext()) {
                TreeItem item = it.next();
                if (Objects.equals(item.getData(), obj)) {
                    return item;
                }
                stack.push(item.getChildren().iterator());
                maxStackSize = Math.max(maxStackSize, stack.size());
            } else {
                stack.pop();
            }
        }
        return null;
    }