0778-swim-in-rising-water.js

/**
 * https://leetcode.com/problems/swim-in-rising-water/
 * @param {number[][]} grid
 * @return {number}
 */
var swimInWater = (grid) => {
    const seen = new Set();
    const minHeap = getHeap(grid);

    return getTime(grid, seen, minHeap);
};

const getHeap = (grid, minHeap = new MinPriorityQueue()) => {
    minHeap.enqueue([0, 0], grid[0][0]);

    return minHeap;
};

var getTime = (grid, seen, minHeap, maxTime = 0) => {
    const [rows, cols] = [grid.length - 1, grid[0].length - 1];

    while (!minHeap.isEmpty()) {
        const { element, priority: cost } = minHeap.dequeue();
        const [row, col] = element;

        seen.add(grid[row][col]);
        maxTime = Math.max(maxTime, cost);

        const isEnd = row === rows && col === cols;
        if (isEnd) return maxTime;

        checkNeighbors(grid, row, rows, col, cols, seen, minHeap);
    }
};

var checkNeighbors = (grid, row, rows, col, cols, seen, minHeap) => {
    for (const [_row, _col] of getNeighbors(row, rows, col, cols)) {
        if (seen.has(grid[_row][_col])) continue;

        minHeap.enqueue([_row, _col], grid[_row][_col]);
    }
};

const getNeighbors = (row, rows, col, cols) =>
    [
        [1, 0],
        [-1, 0],
        [0, 1],
        [0, -1],
    ]
        .map(([_row, _col]) => [row + _row, col + _col])
        .filter(
            ([_row, _col]) =>
                0 <= _row && _row <= rows && 0 <= _col && _col <= cols,
        );