Number of Islands (easy)

**Problem Statement**

Given a 2D array (i.e., a matrix) containing only 1s (land) and 0s (water), count the number of islands in it.

An **island** is a connected set of 1s (land) and is surrounded by either an edge or 0s (water). Each cell is considered connected to other cells horizontally or vertically (not diagonally).

**Example 2**

**Input**: matrix =

**Output**: 3

**Explanation**: The matrix has three islands. See the highlighted cells below.

**Example 1**

**Input**: matrix =

**Output**: 1

**Explanation**: The matrix has only one island. See the highlighted cells below.

**Constraints:**

`m == matrix.length`

`n == matrix[i].length`

`1 <= m, n <= 300`

`matrix[i][j] is '0' or '1'.`

## Try it yourself

Try solving this question here:

Python3

Python3