solution.js

/**
 * @param {number[][]} image
 * @param {number} sr
 * @param {number} sc
 * @param {number} newColor
 * @return {number[][]}
 */
//  DFS
var floodFill = function (image, sr, sc, newColor) {
    const color = image[sr][sc];
    if (color === newColor) {
        return image;
    }

    const maxX = image.length - 1;
    const maxY = image[0].length - 1;

    function dfs (image, x, y) {
        image[x][y] = newColor;
        if (x > 0 && image[x - 1][y] === color) {
            dfs(image, x - 1, y);
        }

        if (y < maxY && image[x][y + 1] === color) {
            dfs(image, x, y + 1);
        }

        if (x < maxX && image[x + 1][y] === color) {
            dfs(image, x + 1, y);
        }

        if (y > 0 && image[x][y - 1] === color) {
            dfs(image, x, y - 1);
        }
    }

    dfs(image, sr, sc);
    return image;
};