BSCS placement exam - how do I brush up on data structures in 4 weeks?

For data structures I'd prioritize linked lists, stacks, queues, and binary search trees over graphs and dynamic programming for a placement context. The latter come up in upper-division courses but most intro/intermediate placements don't go that far into algorithmic complexity.

Discrete math shows up more on these placements than people expect - especially propositional logic, set theory, and basic proof by induction. You don't need to go deep but knowing the vocabulary and basic operations is worth a few days of prep. Khan Academy's discrete math unit covers what you need.

Your LeetCode approach is solid but supplement it with something that explains the concepts, not just the puzzles. The Visualgo.net site lets you watch data structures animate in real time - it made trees and graph traversal click for me way faster than just reading about them.

For placement exams at most programs, the intro programming portion is very testable with just 2-3 weeks of focused review. Focus on control flow, functions, basic OOP, and list/array manipulation. That's the bulk of what separates the intro course skip from having to take it.

I was in almost the exact same spot six months ago. Honestly, the thing that clicked for me was stop trying to memorize implementations and start asking "what problem does this structure solve." Like once I understood that a queue is just about maintaining order and a heap is about always having the min or max ready, the code started making sense instead of just being something to copy.

Four weeks is enough if you stay focused. I'd spend the first two weeks just doing arrays, linked lists, stacks, and queues until you're comfortable, then move to trees and hash maps. Don't skip hash maps, they show up constantly. Big O isn't as scary as it sounds either, it's really just asking "how does this slow down as the input gets bigger." You've got time, just don't try to do everything at once.

Quick update for anyone following this thread -- I'm about three weeks in now and just scored a 71% on a practice set covering arrays, linked lists, and basic sorting. Wasn't where I wanted to be, but honestly it's way better than my first attempt two weeks ago when I was just guessing half the time. I've been drilling one topic per day and doing timed review sessions at night which has helped a lot.

I'm planning to sit the real exam in about 10 days so I'm trying to hit the weak spots hard this week. One thing that helped me realize I had gaps was going through some of the practice questions here, including this section on bscs/questions/computer security and cybersecurity which came up in my program's sample syllabus. If you're in the same boat just keep grinding the practice sets -- the progress feels slow but it does add up.

I actually failed mine the first time, so take this from someone who learned the hard way. I spent the first attempt just reading theory and watching YouTube videos, and honestly it wasn't enough -- the exam tested whether I could actually trace through algorithms on paper, not just explain them. What changed for me was switching to active recall: I'd close my notes and try to write out how a linked list insertion works from scratch, then check myself. I also did a ton of practice questions, including stuff like bscs/questions/computer security and cybersecurity 3 because the exam touched on more than just data structures.

Four weeks is actually enough if you don't spread yourself thin. Pick arrays, linked lists, stacks, queues, trees, and basic sorting -- don't try to master graphs or dynamic programming yet. I'd spend the first two weeks just building things in Python from scratch (no libraries), then the last two weeks hammering practice questions under timed conditions. You've got more Python experience than I did going in, so you're already ahead.

Four weeks is actually enough if you focus on understanding why things work the way they do. When I was prepping I'd get a question wrong and just move on, and that was a huge mistake. What actually helped was forcing myself to explain why the wrong answers were wrong, not just why the right one was right. Like if you're looking at a question about hash table collisions, don't just memorize "open addressing" -- figure out why chaining would be slower in that specific case. That mindset shift made everything click way faster.

Also don't sleep on the security side of CS fundamentals, it shows up more than you'd expect on placement exams. I found some decent practice on bscs/questions/computer security and cybersecurity 3 that helped me see how security concepts connect to data structures (buffer overflows, memory management, etc.). For the four weeks, I'd spend the first two on arrays, linked lists, trees, and graphs, then the last two on sorting algorithms and recursion. Practice on problems you've already seen but try to predict why the distractors look tempting -- that's what the exam is actually testing.