Practice Print Binary Tree

Create a string matrix showing the given binary tree. If its height measured in edges is h, use h + 1 rows and 2^(h + 1) - 1 columns, initially filled with empty strings. Put the root in the middle column of row 0. For a node at row r and column c, place its left child at row r + 1, column c - 2^(h - r - 1), and its right child at row r + 1, column c + 2^(h - r - 1). Store each node's value as a string and return the completed matrix.