Final answer:
When exceeding the threshold on balance at the start of SHAB, the pointerInParent points to the root node.
Step-by-step explanation:
When exceeding the threshold on balance at the start of SHAB, the pointerInParent points to the root node. In a self-balancing binary search tree like SHAB (Scapegoat Tree), the pointerInParent is used to keep track of the parent node during insertion or deletion.
When the balance threshold is exceeded, the tree is restructured to maintain balance, and the root node may change. Therefore, pointerInParent is updated to point to the new root node.