The Problem is this. I made some naive solution which got AC, then I optimized my solution using vectors and I am getting one solution getting WA in C++17 and the same one getting AC in C++20.

AC in C20 175129943

WA in C17 175130535

I for sure know that I am triggering some undefined behavior here or else this wont happen. Maybe its the equality check of vectors using the == operator. But I am not sure.

Thanks.