Rewrite Tree with Subtree Sums

Problem: Rewrite Tree with Subtree Sums Given a binary tree where each node contains an integer value, rewrite every node's value to be the sum of all original values in the subtree rooted at that node. For every node node: node.val = sum(original values of all nodes in node's subtree) Return the rewritten tree. Input Format The first line contains an integer n, the length of the level-order array. The second line contains n tokens representing the binary tree in level order. An integer represents a node value. null represents an empty node. Output Format Print the rewritten tree in level-order traversal, separated by spaces, with trailing null values removed. Constraints 0 <= n <= 10^5 Node value range: -10^9 <= val <= 10^9 The input is guaranteed to represent a valid binary tree. Example 1 Input: 7 1 2 3 4 5 6 7 Output: 28 11 16 4 5 6 7 Explanation: The root becomes 1+2+3+4+5+6+7 = 28. Node 2 becomes 2+4+5 = 11. Node 3 becomes 3+6+7 = 16. Example 2 Input: 7 5 3 8 null 4 null 10 Output: 30 7 18 null 4 null 10 Example Input 7 1 2 3 4 5 6 7 Output 28 11 16 4 5 6 7