Solution: Number of Islands

Statement

Let’s consider a scenario with an $(m \times n)$ 2D grid containing binary numbers, where '0' represents water and '1' represents land. If any '1' cells are connected to each other horizontally or vertically (not diagonally), they form an island. Your task is to return the total number of islands in the grid.

Constraints:

• $1 \leq$ grid.length $\leq 50$

• $1 \leq$ grid[i].length $\leq 50$

• grid[i][j] is either '0' or '1'.

Solution

The key approach is to traverse the 2D grid and join adjacent cell 1s horizontally or vertically. In the end, we return the number of connected components.