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import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
export default function findFrequentTreeSum(root: TreeNode | null): number[] {    const sum_to_count = new Map<number, number>();
    sum(root);    let max = 0;    function sum(root: TreeNode | null): number {        if (!root) return 0;
        const result = root.val + sum(root.left) + sum(root.right);        const count = (sum_to_count.get(result) ?? 0) + 1;
        sum_to_count.set(result, count);        max = Math.max(max, count);        return result;    }
    return [...sum_to_count.entries()]        .filter(([_key, value]) => value === max)        .map((a) => a[0]);}