0733 - Flood Fill.py

class Solution:
    def floodFill(self, image: List[List[int]], sr: int, sc: int, color: int) -> List[List[int]]:
        start = image[sr][sc]
        self.dfs(image, sr, sc, color, start)
        return image

    def dfs(self, image, sr, sc, color, start):
        if sr < 0 or sr > len(image) - 1 or sc < 0 or sc > len(image[0]) - 1 or image[sr][sc] != start or image[sr][sc] == color:
            return 
        image[sr][sc] = color
        self.dfs(image, sr+1, sc, color, start)
        self.dfs(image, sr-1, sc, color, start)
        self.dfs(image, sr, sc+1, color, start)
        self.dfs(image, sr, sc-1, color, start)