【DFS】695.岛屿的最大面积

题目

DFS

Python

class Solution:
    def maxAreaOfIsland(self, grid: List[List[int]]) -> int:
        maxArea = 0
        m, n = len(grid), len(grid[0])
        visited = [[False]*n for _ in range(m)]

        for i in range(m):
            for j in range(n):
                if grid[i][j] == 1 and not visited[i][j]:
                    maxArea = max(maxArea, self.dfs(grid, i, j, visited))
        
        return maxArea
    
    def dfs(self, grid, i, j, visited):
        if (i < 0 or i >= len(grid) 
            or j < 0 or j >= len(grid[0])
            or grid[i][j] == 0 
            or visited[i][j]):
            return 0
        visited[i][j] = True

        return (1 + self.dfs(grid, i-1, j, visited) 
                    + self.dfs(grid, i+1, j, visited)
                    + self.dfs(grid, i, j-1, visited) 
                    + self.dfs(grid, i, j+1, visited))