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)))