tree_traversal

private void levelOrder(Node node){
    // 1. print the root data
    // 2. insert root address in queue
    // 3. while queue is not empty
    //      a. get the address of the queue
    //      check left child has data
    //          i. print the left child data
    //          j. insert data of left child
    //      else check right child has data
    //          i. print the right child data
    //          j. insert data of the right child
    //      timecomplexity = o(n)
    //      spacecomplexity = o(n)

    Queue<Node> queue = new LinkedList<>();
    System.out.print(node.data + " ");
    queue.add(node);

    while (!queue.isEmpty()){
        node = queue.remove();
        if (node.left != null){
            System.out.print(node.left.data + " ");
            queue.add(node.left);
        }

        if(node.right != null){
            System.out.print(node.right.data + " ");
            queue.add(node.right);
        }
    }
}