Doubt in a problem

[Srijeet-Biswas-2268011783479429 (Srijeet Biswas)]

I have this problem
https://gist.githubusercontent.com/sb39/7488f92cf126908b39affd7284f1336c/raw/1283399a27105cb016e0127af5f9b5e1565f658b/problem.cpp

i get runtime Error-SIGSEGV how to avert the error ?
only my sample testcase is passing