Strongly Connected Components

Given a directed graph with n vertices and edges, find the number of strongly connected components. A strongly connected component is a maximal set of vertices where every vertex can reach every other vertex.

Examples
Input: [4,[[0,1],[1,2],[2,0],[2,3]]]
Output: 2
Hints

Strongly Connected Components

Given a directed graph with n vertices and edges, find the number of strongly connected components. A strongly connected component is a maximal set of vertices where every vertex can reach every other vertex.