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Aporeon

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21 results across 1 active filter

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Coding problemMedium~25 min

Calculate invoice total with discounts

Implements invoice total calculation with quantity, unit price, percentage discount, and rounding.

Concept questionEasy~5 min

Choose between an array, List<T>, and LinkedList<T> in C#

Chooses a sequential collection from size, mutation, access pattern, memory locality, and the behavior callers actually need.

.NETC#

Practice drill

Concept questionMedium~7 min

Choose between Join, ToLookup, and repeated scans

Avoids hidden quadratic work by indexing repeated matches while preserving duplicate, missing, ordering, and memory semantics.

Concept questionMedium~7 min

Choose string comparers for keys, membership, and sorting

Separates ordinal identity comparison from culture-aware display ordering and keeps hash-based collection semantics consistent.

Coding problemEasy~15 min

Chunk items for batch processing

Implements chunking for batch processing without dropping final partial batches.

Concept questionMedium~7 min

Collection operation complexity and real runtime costs

Uses complexity as a first filter while accounting for constants, locality, allocations, data size, and the complete operation sequence.

Coding problemMedium~25 min

Compare semantic version strings

Implements comparison for simple semantic version strings with missing patch parts treated as zero.

Coding problemEasy~15 min

Count normalized words in text

Implements a word-frequency counter with normalization, punctuation handling, and stable ordering.

Coding problemMedium~25 min

Deduplicate events by idempotency key

Implements duplicate suppression while preserving the first event for each idempotency key.

Concept questionEasy~5 min

Dictionary and HashSet hashing and equality in C#

Explains how hash-based collections use hash codes and equality, then chooses Dictionary or HashSet from the value the program needs to store.

Coding problemEasy~15 min

Find the first non-repeating character

Implements a stable first-unique-character search using counts and original order.

Coding problemMedium~25 min

Flatten a category tree to paths

Flattens a tree into display paths while preserving order and preventing simple cycles.

Coding problemMedium~25 min

Group orders by customer summary

Builds customer summaries from order rows using grouping, aggregation, and deterministic ordering.

Coding problemHard~35 min

Implement a simple LRU cache

Implements a small LRU cache using a dictionary plus linked list for O(1) get and put.

Concept questionHard~9 min

Know when a loop is clearer and faster than LINQ

Balances declarative transformations with explicit control flow when allocation, early exit, mutation, diagnostics, or complex state matters.

Concept questionMedium~7 min

Materialize LINQ results at clear boundaries

Chooses when to keep a sequence lazy and when to create a stable collection with ToList, ToArray, or another deliberate materialization.

Coding problemMedium~25 min

Merge overlapping time ranges

Implements interval merging for scheduling-style time ranges with sorted output.

Coding problemMedium~25 min

Return the top K frequent values

Implements top-K frequency selection with deterministic tie-breaking.

Concept questionMedium~7 min

Shape data with Select, SelectMany, and GroupBy

Explains the output shape of core LINQ transformations and uses them without hiding empty groups, duplicate keys, or excessive buffering.

Concept questionMedium~7 min

Streaming versus buffering LINQ operators

Distinguishes operators that can yield incrementally from operators that must consume substantial input before producing results.

Concept questionHard~9 min

Stream results with IAsyncEnumerable<T>

Uses async streams for incremental asynchronous production while preserving cancellation, disposal, backpressure expectations, and API boundaries.