Flood Fill LeetCode solution in JavaScript

1
/**
2
 * @param {number[][]} image
3
 * @param {number} sr
4
 * @param {number} sc
5
 * @param {number} color
6
 * @return {number[][]}
7
 */
8
var floodFill = function (image, sr, sc, color) {
9
  const pixelsToCheck = [[sr, sc]];
10
  const startingPixelColor = image[sr][sc];
11
  const directions = [
12
    [1, 0],
13
    [0, 1],
14
    [-1, 0],
15
    [0, -1],
16
  ];
17
  const seenPixels = new Set();
18

19
  if (startingPixelColor === undefined || startingPixelColor === color)
20
    return image;
21

22
  for (const pixel of pixelsToCheck) {
23
    const currentPixelColor = image[pixel[0]]?.[pixel[1]];
24

25
    if (
26
      currentPixelColor === undefined ||
27
      startingPixelColor !== currentPixelColor
28
    )
29
      continue;
30

31
    image[pixel[0]][pixel[1]] = color;
32

33
    for (const direction of directions) {
34
      const newPixel = [pixel[0] + direction[0], pixel[1] + direction[1]];
35
      const pixelString = newPixel.join();
36

37
      if (seenPixels.has(pixelString)) continue;
38

39
      pixelsToCheck.push(newPixel);
40
      seenPixels.add(pixelString);
41
    }
42
  }
43

44
  return image;
45
};