Aptuz Technology Solutions interview questions

I attended the interview at aptuz in March 2017 through AMCAT. The total interview process is three rounds: one is written-coding other two are technical rounds. I cleared first two rounds and rejected in the 3rd round, but I don't know why? In first round itself, they used to tell for optimize the code and to reduce the cost of loops. The second round is the technical interview, asked to write code for, how to reduce the cost of painting houses using 3 colors and adjacent houses should not have same colors. houses are of five streets. I just wrote logic of the problem and explain them well. But after 10days called me for certificates and rejected me without any reason.

I got a email with a problem to solve it after applying to the job. After solving the problem i was called to interview. In the interview i was asked on the approach to solve that problem in email. After that i was given to logical problem. After that i was asked different technical questions and HR questions