In a circular buffer of size n, to advance a write index by one modulo n, compute:

Which in-place procedure deletes the element at index k from a 1D array of length n (shifting remaining)?

What is the minimum number of comparisons required to find both the minimum and maximum element in a 1D array of size n?

Most CSE students prep for interviews by rewatching DSA playlists and re-reading OS notes. That's recognition, not recall — and interviews test recall under pressure.

Here's the shift that actually moves the needle: stop consuming, start retrieving. Instead of rewatching a video on graph traversal, close the tab and try to write out BFS/DFS from scratch. Instead of re-reading DBMS normalization notes, try to explain 3NF out loud to an empty room. If you stumble, that's exactly the gap you needed to find.

The fix is topic-wise active practice: DSA, OS, DBMS, CN, OOPs — one topic at a time, forcing retrieval instead of re-reading. That's the whole idea behind what I've been building at CodeCraft Prep. If you're grinding for placements or finals, try drilling one topic today the hard way (no notes) before you go back to review. You'll find your real gaps in 10 minutes.