Implement / Build a QuadTree for a 2D grid with general values (not just 0/1)

Problem: Implement / Build a QuadTree (values are not limited to 0/1) Given a 2D grid grid representing a square region, where each smallest cell contains a value (not restricted to 0/1; could be any integer), implement a QuadTree data structure from scratch and write a function to construct the QuadTree. QuadTree rules For any node representing a region: The node corresponds to an axis-aligned square subregion. If all cells in the region have the same value, the node is a leaf and stores that value. Otherwise, the node is an internal node and the region is evenly split into 4 quadrants (top-left, top-right, bottom-left, bottom-right); recursively build the 4 children. You should design and implement the node structure yourself (e.g., fields like isLeaf, val, topLeft, topRight, bottomLeft, bottomRight, and optionally boundary coordinates). Input An n x n 2D array grid (n >= 1). Output Return the root node of the constructed QuadTree. Constraints / Notes The region is a square. Each split divides the region into four equal sub-squares. The constructed tree must satisfy: A node is a leaf only if all values in its region are identical. Otherwise it must have exactly 4 children. Sample test ideas (Serialization is up to you, e.g., print nodes in preorder as (isLeaf, val).) n=1: [[5]] -> root is leaf with val=5 n=2 all same: [[7,7],[7,7]] -> root is leaf val=7 n=2 all different: [[1,2],[3,4]] -> root internal, 4 leaf children 1,2,3,4 n=4 quadrant-uniform grid -> root internal, 4 leaf children n=4 requires deeper recursion -> some quadrants must be further split Example Input 1 5 Output (isLeaf=1,val=5)