Practice/Amazon/Leetcode 695. Max Area of Island

Leetcode 695. Max Area of Island

CodingMust

Problem

You are given a 2D grid where each cell contains either 0 (water) or 1 (land). An island is defined as a group of land cells that are connected horizontally or vertically (4-directional connectivity). Diagonal connections do not count.

Your task is to find the area of the largest island in the grid. The area of an island is the number of land cells it contains. If there are no islands in the grid, return 0.

Requirements

1. Implement a function that takes a 2D grid of integers (0s and 1s) as input
2. Return the maximum area among all islands in the grid
3. Only consider 4-directional connectivity (up, down, left, right)
4. Return 0 if no land cells exist in the grid
5. The function should handle grids of any valid dimensions

Constraints

• m == grid.length (number of rows)
• n == grid[i].length (number of columns)
• 1 <= m, n <= 50
• grid[i][j] is either 0 or 1
• Time complexity: O(m × n) is expected
• Space complexity: O(m × n) for the recursion stack or visited tracking

Examples

Example 1:

Input: grid = [ [1,1,0,0,0], [1,1,0,0,0], [0,0,0,1,1], [0,0,0,1,1] ] Output: 4 Explanation: There are two islands with areas 4 and 4. The maximum is 4.

Example 2:

Input: grid = [ [0,0,0], [0,0,0] ] Output: 0 Explanation: No land cells exist, so the answer is 0.

Example 3:

Input: grid = [ [1,1,1,0,0], [0,0,1,0,1], [0,0,1,1,1] ] Output: 6 Explanation: The center/right island has cells at positions forming a connected component of size 6.