Hi Muhammad,

The node that contains the value 10 should have a height of -1, because it only has one node to the left of it and no node to the right. From this we conclude that the height of the node that contains the value 10 is right-left = 0–1 = -1 .

The height of node 22 should be 0, because it has no children so it is therefor already balanced, or we can say its right -left = 0–0 = 0.

Thanks for reading my article!
randerson112358