InterviewBit Problems   Cycle in Undirected Graph : Unsolved

About the Cycle in Undirected Graph : Unsolved category (1)
Memory limit exceeded ? what to do? (7)
Help me why is it wrong for multiple test cases! (2)
Help me in this runtime error (2)
InterviewBit is a joke, you can't submit your feedback(nothing happens on submission). The output I get locally is zero for [1,2] case but your editor shows 1. Very bad patform (3)
For [1,2] test case, I get 0 output in IDE as per my code but it says 1 which is incorrect (1)
Getting runtime error in this code (1)
Hint : Graphs are disconnected :-<. Why ib Whyyy! (1)
Please help me in finding the bug, not correct for a test case (2)
Why do we need to apply DFS for each and every node [1...A] in the graph? (2)
You need to check all the nodes as source node for cycle (2)
Please help in finding the bug. My code is failing on test case 90. I have used DFS approach (3)
Given solution is not correct (2)