The second semester is going to start from 1st January 2019, so you can glance through the syllabus in advance to know the subjects.
These were the books recommended in the year 2018. You can have an idea for the references. I used only PDFs during the first year and the third semester, and it depends on you if you want to buy the book.
II.1 Modeling continuous change through ordinary differential equations and complex analysis
Elementary Differential Equations
by C. Henry Edwards (Author), David E. Penney (Author)
II.2 Understanding real life situation through Discrete Mathematics
Discrete Mathematics and Its Applications
II.3 Decoding Computation Structure and Logic
Introduction to Computer Theory
II.4 Reflecting thought processes through Object Oriented Programming
Java – The Complete Reference