#695

Max Area of Island

medium· Graphsruns: 0

Given a binary matrix grid where 1 represents land and 0 represents water, return the maximum area of an island in grid. The area of an island is the number of cells with value 1 in the island. An island is a 4-directionally connected group of 1s. If there is no island, return 0.

wpm 0acc 100%time 0:000 / 754

class Solution:
    def maxAreaOfIsland(self, grid: list[list[int]]) -> int:
        rows, cols = len(grid), len(grid[0])

        def dfs(r: int, c: int) -> int:
            if (
                r < 0
                or r >= rows
                or c < 0
                or c >= cols
                or grid[r][c] == 0
            ):
                return 0
            grid[r][c] = 0
            return (
                1
                + dfs(r + 1, c)
                + dfs(r - 1, c)
                + dfs(r, c + 1)
                + dfs(r, c - 1)
            )

        best = 0
        for r in range(rows):
            for c in range(cols):
                if grid[r][c] == 1:
                    best = max(best, dfs(r, c))
        return best

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