> ## Documentation Index
> Fetch the complete documentation index at: https://leetcode-py.wisl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> leetcode-py is a Python LeetCode practice environment generator with one CLI: lcpy. It is not a service or platform.
> Each problem is a directory under leetcode/ with README.md, solution.py, test_solution.py, helpers.py, and playground.ipynb. lcpy gen creates them from JSON templates bundled with the package.
> Examples are backed by tests; copy them verbatim.

# Max Area of Island Python Solution with Tests

> Tested Python solution for LeetCode 695 with 13 pytest cases. Generate a practice environment with lcpy.

LeetCode 695, Medium. Topics: Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix. [View on LeetCode](https://leetcode.com/problems/max-area-of-island/description/).

Generate this problem as a practice environment: tested reference solution, 13 [parametrized pytest cases](/practice/testing), and a playground notebook:

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
lcpy gen -n 695   # by problem number
lcpy gen -s max_area_of_island   # by problem name
```

## Problem

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`.

### Examples

![Example 1](https://assets.leetcode.com/uploads/2021/05/01/maxarea1-grid.jpg)

```
Input: grid = [[0,0,1,0,0,0,0,1,0,0,0,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,1,1,0,1,0,0,0,0,0,0,0,0],[0,1,0,0,1,1,0,0,1,0,1,0,0],[0,1,0,0,1,1,0,0,1,1,1,0,0],[0,0,0,0,0,0,0,0,0,0,1,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,0,0,0,0,0,0,1,1,0,0,0,0]]
Output: 6
Explanation: The answer is not 11, because the island must be connected 4-directionally.
```

```
Input: grid = [[0,0,0,0,0,0,0,0]]
Output: 0
```

### Constraints

* m == grid.length
* n == grid\[i].length
* 1 \<= m, n \<= 50
* grid\[i]\[j] is either 0 or 1.

## Solution

Reference implementation from [solution.py on GitHub](https://github.com/wislertt/leetcode-py/blob/main/leetcode/max_area_of_island/solution.py), full suite in [test\_solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/max_area_of_island/test_solution.py):

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
class Solution:
    # Time: O(m * n)
    # Space: O(m * n)
    def max_area_of_island(self, grid: list[list[int]]) -> int:
        if not grid or not grid[0]:
            return 0
        rows, cols = len(grid), len(grid[0])

        def dfs(row: int, col: int) -> int:
            if row < 0 or row >= rows or col < 0 or col >= cols or grid[row][col] == 0:
                return 0
            grid[row][col] = 0  # Mark visited by sinking
            area = 1
            area += dfs(row + 1, col)
            area += dfs(row - 1, col)
            area += dfs(row, col + 1)
            area += dfs(row, col - 1)
            return area

        max_area = 0
        for row in range(rows):
            for col in range(cols):
                if grid[row][col] == 1:
                    max_area = max(max_area, dfs(row, col))
        return max_area
```

## Complexity

| Time      | Space     |
| --------- | --------- |
| O(m \* n) | O(m \* n) |

## Tags

[NeetCode 150](/catalog/neetcode-150), [NeetCode 250](/catalog/neetcode-250), [NeetCode All](/catalog/neetcode).