I tried this problem using sliding window approach. But I couldn't find where i am wrong. I got WA at test case 2 . Is this approach right?

https://codeforces.com/contest/1955/submission/256120722

Any suggestions would be helpful! Thank you

I started competitive programming few weeks ago. After attending some contests and some practice, I was able to solve A problem in div2 contests faster. (sometimes slower too). but the problem is with the problem B. does it consists of topics that one should know before solving? Please share how you guys practiced to get good at solving B. Thank you.

Please share your suggestions, guys. It will be very helpful..