Number of closed islands [2 solutions]

In this article, we have explored how to find the Number of closed islands in a graph. We have presented two approaches using the concept of BFS/ DFS and Union Find.

Pre-requisites:

BFS and DFSUnion FindProblem Statement

Given a 2-D grid consists of 0s (land) and 1s (water). An island is a maximal 4-directionally connected group of 0s and a closed island is an island totally (all left, top, right, bottom) surrounded by 1s.

Return the number of closed islands.

Example:

Output: 2

Explanation:...