Issues with height calculation

[shrivalidutt]

Logical Errors:

The height calculation during rotations is incorrect. The height should be updated after the rotations, but it’s using the old height values.
The insertion logic does not account for duplicate values. In an AVL tree, typically duplicates are either not allowed or handled in a specific way.
Performance Issues:

The height calculation can be optimized by maintaining the height in the node itself during insertion instead of recalculating it every time.
The populate and populatedSorted methods can be more efficient.