Number of Islands

graphs · function

Description

Given a 2D grid of '1' (land) and '0' (water), count the number of
islands. An island is a maximal group of '1' cells connected
horizontally or vertically (NOT diagonally).

Example:
    grid = [["1","1","0"],
            ["1","0","0"],
            ["0","0","1"]]
    -> 2 islands (the L-shape in the top-left, and the lone '1' at bottom-right)

Constraints

- Grid dimensions up to 300x300
- Cells are strings '0' or '1' (not ints)
- Diagonal connections don't count
- Empty grid returns 0
solution.py
output
Run the cases to see results here.