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Advanced Algorithms and Problem Solving Questions

Comprehensive assessment of advanced algorithmic reasoning, design, and optimization for hard and composite problems. Covers advanced dynamic programming techniques including state compression and bitmask dynamic programming, combinatorial generation and backtracking, recursion and divide and conquer strategies, greedy algorithms with correctness proofs, and advanced graph algorithms such as breadth first search, depth first search, shortest path algorithms including Dijkstra and Bellman Ford, minimum spanning tree, network flow, strongly connected components, and topological sort. Also includes advanced tree and string algorithms such as suffix arrays and advanced hashing, bit manipulation and low level optimizations, algorithmic reductions and heuristics, and complexity analysis including amortized reasoning. Candidates should recognize applicable patterns, combine multiple data structures in a single solution, transform brute force approaches into optimized solutions, prove correctness and derive time and space complexity bounds, handle edge cases and invariants, and articulate trade offs and incremental optimization strategies. At senior levels expect mentoring on algorithmic choices, designing for tight constraints, and explaining engineering implications of algorithm selection.

EasyTechnical
23 practiced
Explain amortized analysis using the dynamic array resizing example. Show the total cost of performing n append operations when the array doubles capacity on overflow and compute the amortized cost per append. Then compare this to resizing by a factor of 1.5 and discuss practical implications for write-heavy ingestion pipelines and memory fragmentation.
HardTechnical
24 practiced
Sketch a reduction from 3-SAT to a resource-constrained scheduling or allocation problem to argue NP-hardness at a high level (construction is sufficient). Then propose practical heuristic approaches you would recommend to a data-engineering team for near-optimal scheduling: greedy with local search, integer linear programming relaxations, simulated annealing, and explain trade-offs, expected runtimes, and how you'd measure solution quality in production.
EasyTechnical
17 practiced
You need to detect occurrences of a fixed pattern (length m) in an unbounded log stream with minimal latency and O(1) extra memory per processed character. Describe and implement the streaming variant of Knuth-Morris-Pratt (KMP) or Rabin-Karp in Python suitable for this purpose. Discuss memory/time complexity, collision risk for rolling hash, and how to safely update the pattern without stopping the stream.
EasyTechnical
16 practiced
Explain when to choose a hash-based join vs. a sort-merge join in a distributed data pipeline. Compare algorithmic complexity, memory and network IO, skew robustness, support for range predicates, and operational considerations (e.g., ease of checkpointing, fault tolerance). Give examples from Spark or MapReduce environments.
MediumTechnical
19 practiced
Implement the Misra-Gries (Frequent) algorithm in Python to find all elements that occur more than n/k times in a stream. Include code, explain the memory guarantees, and show how to merge counters from multiple workers to get a correct global heavy-hitter set with provable guarantees.

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