Flood Fill

Hello, Here’s my solution for the flood fill problem, found on LeetCode. If you want me to write about certain topics please let me know in the comments, thank you! Link to the problem: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 """ An image is represented by a 2-D array of integers, each integer representing the pixel value of the image (from 0 to 65535). Given a coordinate (sr, sc) representing the starting pixel (row and column) of the flood fill, and a pixel value newColor, "flood fill" the image. To perform a "flood fill", consider the starting pixel, plus any pixels connected 4-directionally to the starting pixel of the same color as the starting pixel, plus any pixels connected 4-directionally to those pixels (also with the same color as the starting pixel), and so on. Replace the color of all of the aforementioned pixels with the newColor. At the end, return the modified image. """ from typing import List, Tuple class Solution: def __init__(self): self.visited = set() def _set_pixel(self, image: List[List[int]], point: Tuple[int, int], value: int): try: image[point[0]][point[1]] = value except IndexError: pass def _get_pixel(self, image: List[List[int]], point: Tuple[int, int]): if point[0] < 0 or point[1] < 0: return None try: return image[point[0]][point[1]] except IndexError: return None def _floodFill(self, image: List[List[int]], point: Tuple[int, int], color: int, newColor: int) -> List[List[int]]: pixel = self._get_pixel(image, point) if pixel is not None and pixel == color and point not in self.visited: self.visited.add(point) self._set_pixel(image, point, newColor) self._floodFill(image, (point[0], point[1] + 1), color, newColor) self._floodFill(image, (point[0], point[1] - 1), color, newColor) self._floodFill(image, (point[0] + 1, point[1]), color, newColor) self._floodFill(image, (point[0] - 1, point[1]), color, newColor) def floodFill(self, image: List[List[int]], sr: int, sc: int, newColor: int) -> List[List[int]]: point = (sr, sc) pixel = self._get_pixel(image, point) self.visited = set() if pixel is not None: self._floodFill(image, point, pixel, newColor) return image if __name__ == '__main__': s = Solution() out = s.floodFill([[1,1,1],[1,1,0],[1,0,1]], 1, 1, 2) print("Output", out) assert out == [[2,2,2],[2,2,0],[2,0,1]] out = s.floodFill([[0,0,0],[0,0,0]], 0, 0, 2) print("Output", out) assert out == [[2,2,2],[2,2,2]] out = s.floodFill([[0,0,0],[0,1,1]], 1, 1, 1) print("Output", out) assert out == [[0, 0, 0], [0, 1, 1]]