Here is the link to the problem: https://www.hackerearth.com/practice/algorithms/graphs/depth-first-search/practice-problems/algorithm/parwal-problem/ What should be approach and how can I solve these problem?
Here is the link to the problem: https://www.hackerearth.com/practice/algorithms/graphs/depth-first-search/practice-problems/algorithm/parwal-problem/ What should be approach and how can I solve these problem?
Having idea of rerooting will help you in solving this problem.
Here is a blog, in it's comments section you can find useful resources.LINK