WA after many attempts

Hi everyone!
I’ve written my code for a problem, declared all the data as unsigned long long int, tried many many test cases. Works completely fine on my PC. Can anybody give a hint as to what can possibly be the causes of WA?

do not ask contest questions on forum

@raul1rnjn535_3 I’m not asking the answer to GUESS, I’m just asking possible reasons for getting WA on Codechef because the code runs fine on my PC.

I’m sorry, I’ve edited the question, could you please help.

Its 100% not test primer problem or something, so just go and fix your code?

There are 3 main reasons for getting a Wrong Answer

  1. You misunderstood the problem statement. It feels that the code runs fine for you because you’re answering a different problem.

  2. There is a bug in your implementation that is triggered rarely. In this case, it’s usually good to write a purely brute force solution and check the answers of both programs against either manually created test cases or random ones.

  3. You think your algorithm is correct but it actually isn’t. A brute force may help checking this.