ou are given an m x n integer matrix grid​​​, where m and n are both even integers, and an integer k. The matrix is composed of several layers, which is shown in the below image, where each color is its own layer: A cyclic rotation of the matrix

rotateGrid.js

/**
 * @param {number[][]} grid
 * @param {number} k
 * @return {number[][]}
 */
var rotateGrid = function(grid, k) {
    const m = grid.length, n = grid[0].length;
    const layers = Math.min(m, n) / 2;

    for (let layer = 0; layer < layers; layer++) {
        let ring = [];

        let top = layer, bottom = m - layer - 1;
        let left = layer, right = n - layer - 1;

        // top row
        for (let j = left; j <= right; j++) ring.push(grid[top][j]);
        // right col
        for (let i = top + 1; i <= bottom; i++) ring.push(grid[i][right]);
        // bottom row
        for (let j = right - 1; j >= left; j--) ring.push(grid[bottom][j]);
        // left col
        for (let i = bottom - 1; i > top; i--) ring.push(grid[i][left]);

        const L = ring.length;
        const kmod = k % L;
        const rotated = ring.slice(kmod).concat(ring.slice(0, kmod));

        let idx = 0;

        // write back: top row
        for (let j = left; j <= right; j++) grid[top][j] = rotated[idx++];
        // right col
        for (let i = top + 1; i <= bottom; i++) grid[i][right] = rotated[idx++];
        // bottom row
        for (let j = right - 1; j >= left; j--) grid[bottom][j] = rotated[idx++];
        // left col
        for (let i = bottom - 1; i > top; i--) grid[i][left] = rotated[idx++];
    }

    return grid;
};