You are given an m x n binary matrix grid. An island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.
The area of an island is the number of cells with a value 1 in the island.
Return the maximum area of an island in grid. If there is no island, return 0.
class Solution: def maxAreaOfIsland(self, grid: List[List[int]]) -> int: ROWS, COLS = len(grid), len(grid) visit = set() def dfs(r, c): if ( r < 0 or r == ROWS or c < 0 or c == COLS or grid[r][c] == 0 or (r, c) in visit ): return 0 visit.add((r, c)) return 1 + dfs(r + 1, c) + dfs(r - 1, c) + dfs(r, c + 1) + dfs(r, c - 1) area = 0 for r in range(ROWS): for c in range(COLS): area = max(area, dfs(r, c)) return area