Grokking Graph Algorithms for Coding Interviews
Ask Author
Back to course home

0% completed

Vote For New Content
Number of Islands (easy)
Table of Contents

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

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.

**Constrain

.....

.....

.....

Like the course? Get enrolled and start learning!

Table of Contents

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible