right-left rotiation (rlor "double rightnotes double right rotationor right-left rotationor simply rlis rotation that must be performed when attempting to balance tree which has left subtreethat is right heavy this is mirror operation of what was illustrated in the section on left-right rotationsor double left rotations let' look at an example of situation where we need to perform right-left rotation in this situationwe have tree that is unbalanced the left subtree has height of and the right subtree has height of this makes the balance factor of our root nodecequal to - what do we dosome kind of right rotation is clearly necessarybut single right rotation will not solve our problem let' try ita looks like that didn' work now we have tree that has balance of it would appear that we did not accomplish much that is true what do we dowelllet' go back to the original treebefore we did our pointless right rotationc the reason our right rotation did not workis because the left subtreeor ' 'has positive balance factorand is thus right heavy performing right rotation on tree that has left subtree that is right heavy will result in the problem we just witnessed what do we dothe answer is to make our left subtree left-heavy we do this by performing left rotation our left subtree doing so leaves us with this situationc lovely professional university