lets suppose i have this tree

the node with data = 35 was the last node added and has thrown the balance out of wack.

balance of 35 = 0 left 0 right

balance of 40 = 1 left 1 right ....still ok

balance of 30 = 1 left 2 right... still ok

balance of 20 = 1 left 3 right ... problem

so 20 is the first unbalanced node.

q1) is that a right right left problem?

q2) if so do i solve it with a left right rotation

q3) how do i decide which is the rt node and which nodes are A B and C ie which node do i rotate about and keep track of its children and grandchildren