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import { intersection } from "../deps.ts";
export default function pacificAtlantic(heights: number[][]): number[][] {    const m = heights.length;    const n = heights[0]?.length;    if (!m || !n) {        return [];    }    const pacific = new Set<`${number},${number}`>();    const atlantic = new Set<`${number},${number}`>();    for (let i = 0; i < m; i++) {        //左边界        dfs(i, 0, m, n, pacific, heights);    }    for (let j = 1; j < n; j++) {        //上边界        dfs(0, j, m, n, pacific, heights);    }    for (let i = 0; i < m; i++) {        //右边界        dfs(i, n - 1, m, n, atlantic, heights);    }    for (let j = 0; j < n - 1; j++) {        //下边界        dfs(m - 1, j, m, n, atlantic, heights);    }
    const result: number[][] = intersection([...pacific], [...atlantic]).map(        (pos) => {            const [x, y] = pos.split(",");            return [Number(x), Number(y)];        },    );
    return result;}
function dfs(    row: number,    col: number,    m: number,    n: number,    pacific: Set<`${number},${number}`>,    heights: number[][],) {    const dirs = [        [-1, 0],        [1, 0],        [0, -1],        [0, 1],    ];    const key: `${number},${number}` = `${row},${col}`;    if (pacific.has(key)) {        return;    }    pacific.add(key);
    for (const dir of dirs) {        const newRow = row + dir[0],            newCol = col + dir[1];        if (            newRow >= 0 &&            newRow < m &&            newCol >= 0 &&            newCol < n &&            heights[newRow][newCol] >= heights[row][col]        ) {            dfs(newRow, newCol, m, n, pacific, heights);        }    }}