Cognizant Programming Analyst Trainee interview questions

written aptitude round followed by 1:1 interview (2 rounds) general question from resume and data structure concepts like stacks queues tree etc and basic c programming questions and was told to write snippets and finally HR round

Computer Networks, All software projects you've done. You should be able to explain and justify its credibility. Basic algorithmic questions. Sorting, searching, trees graphs and stuff. He argued with me a lot about all my projects. I felt offensive and had to defend myself a lot. I could not believe i got the offer as the interviewer did not show me any positive response.