Flatten BinaryTree

gistfile1.txt

public void flatten(TreeNode root) {
    while (root != null) {
        if (root.left != null) {
            // find the right most in left subtree
            TreeNode rightMostInLeft = root.left;
            while (rightMostInLeft.right != null) {
                rightMostInLeft = rightMostInLeft.right;
            }
            rightMostInLeft.right = root.right;
            root.right = root.left;
            root.left = null;
        }
        root = root.right;
    }
}