Cognizant Software Developer interview questions

Interview was bit tough. Interviewer asked a lot of questions from core sector. Also told me to solve some programming questions.Then asked to solve a differential equation problem suddenly. Then asked to find the largest term in the array,second largest term also.

So first you have to write online exam, then after a few weeks there's the interview They asked about why I wanted to join cognizant; questions from my resume. About my achievements. They gave me two simple aptitude questions.