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import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
export function level(nodes: TreeNode[], output: (r: number[]) => void) {    if (nodes.length === 0) return;
    output(nodes.map((n) => n.val));
    level(        nodes            .map((n) => [n.left, n.right].filter(Boolean) as TreeNode[])            .flat(),        output,    );}