Given Tree
TreeNode * root = new TreeNode ( 0 ) ; root -> left = new TreeNode ( 1 ) ; root -> right = new TreeNode ( 0 ) ; root -> left -> left = new TreeNode ( 0 ) ; root -> left -> right = new TreeNode ( 1 ) ; root -> right -> left = new TreeNode ( 1 ) ; root -> right -> right = new TreeNode ( 1 ) ;