Lesson 44.6 · Interview Method and Simulation
Am I Ready? The Readiness Checklist
You're ready for coding rounds when you can do the listed tasks for each topic from a blank file, within time, and explain them. Use this checklist to find gaps, then go back to that module.
14 min
Think of it like this
A pilot doesn't decide they're ready because they read the manual: they tick off a checklist of manoeuvres they can actually perform. Coding rounds work the same way.
1.Topic by topic: you can…
Arrays and strings: two-pointer and sliding-window problems; prefix sums; Kadane; in-place edits; frequency counting with an int[26] or a map.
Hashing: two-sum style lookups; grouping by a computed key; subarray sums with prefix + map; explain average O(1) and when it degrades.
Linked lists: reverse (iteratively and recursively), find the middle and detect cycles with fast/slow pointers, merge lists with a dummy node, solve LRU.
Stack and queue: matching brackets; monotonic stack for next greater/smaller; monotonic deque for window maximum; BFS with a queue.
Searching: binary search on an index and on the answer, with correct bounds every time; rotated arrays.
Recursion and backtracking: subsets, permutations, combinations with pruning and duplicates; N-Queens style constraint search.
Trees: all traversals iteratively and recursively; height/diameter/path-sum style "return a value, update a global"; BST validation and k-th smallest; LCA; serialize/deserialize.
Heaps: top-K, two heaps for medians, K-way merge; explain sift up/down.
Graphs: build adjacency lists; BFS shortest path; DFS components; cycle detection; topological sort; union-find; Dijkstra; MST.
DP: define state, transition, base case and order for 1D, grid, knapsack, LIS/LCS/edit distance and interval problems; reduce memory with rolling arrays.
Greedy and bits: prove a greedy choice or find the counterexample; XOR tricks and masks.
Design: LRU/LFU, min/max stack, time-based store, iterator, rate limiter; explain complexity per operation.
2.Practice mix and what "complete" means
Mix: roughly 20% easy (warm-ups and new patterns), 60% medium (the level most rounds use) and 20% hard. Mix topics in a week instead of finishing one topic for a month.
Complete means you can, for any common pattern: recognise it from the wording, state the brute force and its cost, find the bottleneck, write the optimal solution cleanly in about 25–35 minutes, test it by hand including edge cases, and explain the trade-offs. Finishing this course's modules, the Core 100 and six timed mock rounds is designed to get you there.
No course can promise a result in every interview: questions vary and nerves are real. What this course does guarantee is coverage of the patterns and problem types that coding rounds draw from, and a method that works under pressure. Keep revising your logged misses and doing timed mocks until the checklist above feels routine.
Quick check
You can solve tree problems with hints but not from a blank file in 30 minutes. What do you do?
Remember
- Ready = from a blank file, on time, explained.
- About 20/60/20 easy/medium/hard.
- Use the checklist to pick what to revise next.
Common mistakes
- Judging readiness by the number of problems solved instead of by unaided, timed solves.