New AVL Tree Exercise

[atilante]

• [x] add the new layout design picture to git
• [x] copy AVL tree exercise code from version.aalto.fi / traky repository to testbench here (@atilante knows how to do this)
• [x] implement the new design
• [x] define each pointer operation in the model answer as a gradable step

[atilante]

Additional notes:

• Design of AVL tree double rotation
  • Archie likes the idea of putting code aside, not on the top
  • Left better than right
  • automatic reflow of code, even with scrollbars
  • Archie agrees that the code cannot be simplified
  • what if each of the four blocks were minimized in the C code, then the user has to click open the right block?
  • or code annotation (mouse hover, even displaying the subtree configuration)
  • Problem: too few steps in the model answer (cognitive overload -> instructional video:
    1. recently added node
    2. inbalanced node
    3. type of inbalance (rotation: L, R, LR, RL?)
    4. pointer manipulations of the rotation one by one