I Can't find error in my solution https://ideone.com/k5OTdF for the problem https://codeforces.me/gym/102942/problem/E. Can anyone give me any test case for which my code is wrong?

https://codeforces.me/problemset/problem/1175/C can anyone explain the solution of this problem please? why should we check for the range of consecutive k elements here? solution is here 55178770