I have been trying to debug my code for hours still don't know why my code is printing wrong answer.Actually I am trying to find number of connected components of a graph.Please help me in this regard.Thank you _/_ .Question link

Kindly give me approach to solve this problem ?Is there any algorithm behind this ?

Hello,I want to do this question which is tagged bitmasking.I am not getting how to solve this.Can anybody give me an approach how do I solve this ?