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import { TreeNode } from "../mod.ts";
export default function verticalTraversal(root: TreeNode | null): number[][] {    const res = [] as number[][];    if (!root) return res;    let current = [[0, 0, root]] as [number, number, TreeNode][];    const map = new Map<number, [number, number][]>();    while (current.length > 0) {        const next = [] as [number, number, TreeNode][];
        for (const [x, y, node] of current) {            const arr = map.get(x) ?? ([] as [number, number][]);            map.set(x, arr);            arr.push([y, node.val]);            if (node.left) next.push([x - 1, y + 1, node.left]);            if (node.right) next.push([x + 1, y + 1, node.right]);        }
        current = next;    }
    for (        const arr of Array.from(map)            .sort((a, b) => a[0] - b[0])            .map((a) => a[1])    ) {        res.push(            arr                .sort((a, b) => (a[0] === b[0] ? a[1] - b[1] : a[0] - b[0]))                .map((a) => a[1]),        );    }    return res;}