Mirror image of a binary tree

Question

Suppose there is a tree:

             1
            / \\
           2   3
              / \\
             4   5

Then the mirror image will

Answer 1

An iterative solution:

public void mirrorIterative() {
    Queue<TreeNode> nodeQ = new LinkedList<TreeNode>();
    nodeQ.add(root);
    while(!nodeQ.isEmpty()) {
        TreeNode node = nodeQ.remove();
        if(node.leftChild == null && node.rightChild == null)
            continue;
        if(node.leftChild != null && node.rightChild != null) {
            TreeNode temp = node.leftChild;
            node.leftChild = node.rightChild;
            node.rightChild = temp;
            nodeQ.add(node.leftChild);
            nodeQ.add(node.rightChild);
        }
        else if(node.leftChild == null) {
            node.leftChild = node.rightChild;
            node.rightChild = null;
            nodeQ.add(node.leftChild);
        } else {
            node.rightChild = node.leftChild;
            node.leftChild = null;
            nodeQ.add(node.rightChild);
        }
    }
}