Connect Next Pointers in Perfect Binary Tree

To solve this efficiently for a system like Netflix's, I would avoid the standard BFS queue approach because it requires O(N) auxiliary space. Instead, since the input is a perfect binary tree, we can exploit the structure to achieve O(1) space complexity. My approach involves traversing level by level using only the next pointers already present. Starting at the root, I iterate through each node at the current level. For every node, I connect its left child to its right child directly. Then, if the current node has a next pointer, I connect its right child to the left child of that next node. By moving to the next node in the row, I effectively stitch together the entire next level before moving down. Once I reach the end of a level, I drop down to the leftmost node of the next level and repeat. This method ensures every node points to its immediate right neighbor or NULL, processing the entire tree in a single pass with minimal memory footprint, which is ideal for large-scale data processing environments.