I have been stuck in this situation for sometime. Actually I get the logic for solving 2.B in sufficient time but am stuck in one or two pretest. Like for the submission, I am not able to resolve the issue (pretest 5). Please suggest some good practices and how to build logic taking care of corner cases, or writing efficient code.

My submission is: https://codeforces.me/contest/1877/submission/227200089

Please help me taking example for this problem.