Detect Cycle in a Directed graph using colors

Given a directed graph, check whether the graph contains a cycle or not. Your function should return true if the given graph contains at least one cycle, else return false.

Example:

Input: n = 4, e = 6 
0 -> 1, 0 -> 2, 1 -> 2, 2 -> 0, 2 -> 3, 3 -> 3 
Output: Yes

Detect Cycle in a Directed graph using colors: https://www.geeksforgeeks.org/detect-cycle-direct-graph-using-colors/