代码题库

Quote Engine Active Set: Peak Concurrently-Live Quotes

Add Two Binary Strings

Array Product Except Self

Credit-Based Backpressure — Replay Producer/Consumer Events into a State Trace

Multi-Feed Bar-Sync Period: LCM Modulo p

Binary-State Strategy — Best PnL With Post-Exit Cooldown

Best Single Trade in a Day

Best Trades With K Transactions and Fee

Leftmost Index via Binary Search (bisect_left)

Backward Induction on a Generic Binary Tree

Invert Binary Tree (Mirror)

Maximum Depth of a Binary Tree (Recursive)

Symmetric Binary Tree Check

American Put Pricing on a CRR Binomial Tree

Per-Position Flag Bitmask Queries

Periodic Yield To Maturity of a Fixed-Rate Coupon Bond via Bisection

Bounded K Transactions: 2D DP for Maximum Profit

Multi-Strike Portfolio with Per-Strike Share Cap (Bounded Knapsack)

Best Realized PnL Bound Under K Disjoint Round-Trips with Per-Roundtrip Impact Cost

Trade-Size Tier Histogram via Right-Inclusive Edges

Bucket-Sort P&L Histogram

Budgeted Whole-Share Portfolio

Build Largest P&L Signal-Strength String

Canonical Ticker-Symbol Form — Cross-Venue Dedup

Pre-Aggregation Bucket Labels: Canonical-Form Group IDs for Multi-Venue Symbols

Card Shuffle Bias Detection

Periodic IRR of an Equally-Spaced Cashflow Stream Under the Standard-Project Assumption via Bisection

Closer-Stronger Bid Distance (Bidirectional): Min of Prev / Next Strictly-Higher Bid

Closest Trade Pair to Target Notional

Cluster Correlated Tickers

Compact a Ring-Buffer of Ticks into Evenly-Bucketed Time Slices

Consolidated Best-Bid Stream Across K Venue Quote Feeds

Factor Cluster Count: Connected Components on a Thresholded Correlation Graph

Count K-Tick Windows With Every Quote Inside the Tolerance Band

Win-Count Leaves on a Forward Scenario Tree

Count of Strictly-Positive Net-Inflow K-Period Windows

Count Regime Paths Satisfying Constraint

Counterparty Activity Shift: Largest Trade-Count Differential Across Two Sessions

Counterparty Gross-Notional Aggregator: Magnitude-Sorted Roll-Up

Cross-Tape Buy-Above-Sell Routing-Quality Alert Count

Cross-Feed Cumulative-Count Lead Exchanges

Worst Cross-Feed Closest-Match Paired Lag

Cross-Feed Tick Match Count Within Tolerance Window

Cross-Feed Unmatched Tick Counts Per Side Within Tolerance

Cumulative PnL Drawdown Alert: Sorted Indices Underwater Beyond Threshold

Cumulative PnL Zero-Crossings: Count Sign Flips of the Backtest Equity Curve

Cumulative Volume Snapshot

Cumulative VWAP at Each Tick

Currency Arbitrage Cycle Detection (Bellman-Ford on Log Rates)

DAG Multi-Worker Topological Schedule

DAG Schedule on K Machines with Critical-Path Priority

Days Until a Better PnL

Counterparty Rotation Indicator: Day-Over-Day Symmetric-Difference Series

Recursive Binary Decision-Tree Evaluator

Deduplicate a Replayed Tick Stream by (ts, exchange-seq), Latest-Ingest Wins

Deepest No-Drawdown Leaf on a Forward Scenario Tree

Per-Side Dense-Rank Annotation for the Day's Blotter

Open-Order Dashboard Tile: Distinct Symbols Currently In Play

Divide-and-Conquer Sum Tree (Parallel Reduction Simulation)

Downsample a Tick Stream into OHLCV Bars (Right-Closed)

Earliest End-Day Reaching A Cumulative Inventory Target From Each Starting Day

Sequenced Limit Orders — Earliest K-th Fire Day With Per-Order Threshold And Cooldown Gap

Earliest K-Period Window Whose Cumulative Return Meets A Sum Target And Whose Worst Single Period Stays Above A Floor

Earliest K-Day Window Whose Population Variance Strictly Exceeds A Spike Threshold

Edit Distance for Ticker-Symbol Mapping

Weighted Edit Distance with Per-Character Cost Matrices

Enumerate Hedge Decompositions

Factor Dependency Topo Order: Deterministic Min-Heap Kahn for Nightly Rebuild

Fan-Out / Fan-In Coordination — Event Replay

Fill Attribution by Parent Order ID

Find the Pivot Index of a P&L Stream

Find Third Largest Distinct

First Day Cumulative PnL Crosses Threshold

First Duplicate Order ID

Fills-Audit Frequency Probe: First Order-ID Whose Lifecycle Hits Exactly k FIX Events

First Unique Character

FIX-Style Trailing Checksum Verify: Trinary Label Per Pipe-Delimited Message

FIX-Style Tag Extract: First Value for a Numeric Tag in a Pipe-Delimited Message

FizzBuzz

Fork-Join Segment Stats (Welford Pairwise Merge)

Forward-Fill Missing Minutes Within a Trading Session

GCD of Share Lots — Round-Lot Reconciliation

Universal Tick Unit: GCD of Per-Venue Tick Sizes

Greenwald-Khanna Streaming Quantile Summary

Count Connected Components in an Undirected Graph

Detect a Cycle in an Undirected Graph

Greedy Coin Change on a Canonical Denomination Set

Minimum Fee-Tier Selection to Cover a Target Volume Range

Walking the Book: Greedy Minimum-Cost Fill

Minimum Platforms for a Railway Schedule

Minimum Cost Path Through a Grid

Maximum P&L Path Through a Grid

HDR Histogram Recorded-Value Bucket Index and Quantile Estimate

Highest K-Day Range

Black-Scholes Implied Volatility on a Strictly Increasing Price Curve via Bisection

Incremental Largest Cluster Size: Streaming Union-Find on a Factor-Pair Edge Tape

Insert and Merge Order-Book Price-Level Intervals

Inverse Percentile Rank of Daily PnL Against Reference Distribution

Jump Game — Can You Reach the Last Index

Jump Game II — Minimum Jumps to Reach Last Index

K-Day Momentum Hits

K-Day Rolling Mean Filter

Budget-Constrained Ticker Selection (0/1 Knapsack)

Minimum Eating Speed (Binary Search on the Answer)

Largest Factor Cluster Size: Maximum Connected Component on a Thresholded Correlation Graph

Largest Divisible Pair (Sort + Scan)

Largest Rectangle in Order Book Depth

Largest Volume Rectangle in a Histogram

Leaky-Bucket Rate Limiter as Admission Control

Longest Consecutive Sequence (Hash Set)

Longest Contiguous Window of Volumes Within an Impact Budget

Longest Palindromic Substring

Longest Stable Trading Streak

Longest Stair-Stepping Subsequence Of Cumulative-PnL Reports Under A Minimum-Gain Gate

Longest Sub-Window Beating a PnL Target via Monotonic-Stack on Prefix Sums

Longest Substring Without Repeating Characters

Longest Trailing Window Whose Absolute-Return Sum Stays Within a Volatility Budget

MapReduce Group-By Count (Two-Phase Aggregation)

Match Bid and Ask Snapshots

Maximum Cumulative Carry Under a Bounded Sign-Flip Budget

Maximum Realised Cumulative Return When Allowed To Skip At Most K Periods

Winning-Streak Counting — Maximum Disjoint Positive-Sum Runs of Minimum Length

Maximum Grid PnL Path With At-Most-K Cell Skips (Right/Down)

Max Non-Overlapping Trade Windows

Single-Session Child-Order Scheduling with FIX Reconfigure Gap

Maximum Profit Over Bounded-Drawdown Window

Disjoint Risk-Bucket Hedge Selection under a Bucket-Budget Bitmask

Max-Reward Sequence Alignment Across Trade-Action Streams

Maximum Total Reward From Timestamped Trade Candidates Under A Compliance Hold-Period Gap

Three-State Action Path — Max Cumulative Reward With Flat Per-Flip Switching Penalty

Max Sum of a Min-Step-Monotone Reward Subsequence (Stair-Step PnL Ceiling)

Max Sum of Fixed-Size Window

Maximum Child-Order Throughput With Per-Order Durations And A FIX-Session Gap

Maximum Concurrent Trades

Merge Per-Day Bar Shards into a Sorted Timeseries

Merge K Quote Streams with Lineage

Merge K Sorted Trade Streams

Merge K Per-Venue Trade Tapes Into One Chronological Stream

Top-N Recent Items From Per-Source News Feeds

Merge Overlapping Quote-Validity Windows

Merge Two Sorted Lists — Iterative Two-Pointer

Merge Two Trade Tapes

Min Cancels for Quote Stability

Throttle-Window Compliance Replay: Minimum Order Cancels

Min Cash Buffer to Survive

Min Contracts to Cover Greek Buckets via Bitmask BFS

Minimum Cost for Train Travel Passes

Regime-Stability Segmentation — Fewest Bounded-Spread Runs Over A Return Stream

Earliest Second Where the Algo Hits Its Volume Target Without Tripping the Slippage Cap

Minimum Constant Maker Fill-Rate to Meet a Parent-Order Deadline Under Per-Minute Supply Caps

Position-Band Governance: Minimum Flatten-Resets to Stay Inside [-L, +L]

Minimum Flips for Monotone Up-Day Pattern

Best Single Round-Trip Realized PnL Under a Minimum-Holding-Period Compliance Rule

Min Hops to Core Factor Set: Multi-Source BFS on a Factor-Similarity Graph

Minimum Knight Moves — BFS on an Infinite Board

Calibrating the Minimum Leverage Cap for a Target Risk Budget

Largest Uniform Collateral Haircut Covering a Liability via Bisection

Minimum Max-Drawdown Across Root-to-Leaf Paths

Tear-Sheet Bucketing — Fewest Strictly-Positive-Sum Cover Chunks With Per-Block Length Cap

Hedge-Inventory Replenishment: Minimum Top-Ups to Stay Non-Negative

Min Replenishments to Avoid Stockout

Minimum Concurrent Streaming Jobs for Execution Windows

Smallest Router Count under a BFD Load-Cap Assigner via Bisection

Minimum Routers with FIX-Session Setup Delay

Smallest Slippage Cutoff Meeting a Target Absolute Weighted Cost via Bisection

Minimum Spread Tolerance for Target Fill Rate

Min-Stack with O(1) get_min

Smallest Stress Severity Factor Where a Counterparty First Breaches Its Cap

Minimum Tickers for Liquidity Coverage

Smallest Slice Length Whose Every Window Meets a Volume Target

Minimum Window Substring

Misra-Gries (k-1)-Counter Heavy-Hitters Over a Trade-Tape Stream

Order-Event Footprint: Most-Frequent Consecutive Event-Pair

Tape-Anomaly Detector: Most-Repeated Trade Fingerprint

End-of-Day Net Positions from a Raw Trade Tape

Time-to-New-All-Time-High: First Future Index Strictly Above the Running Peak

Next Depth-Jump within a Forward Window: Bounded-Distance Ratio-Threshold Scan over a Best-Bid-Depth Tape

Next Greater Quote Timestamp

Next Smaller Element Index

Min Rebalance Windows To Remove

Min Intervals To Remove For Non-Overlap

Notional by Venue, Ranked

Lag-1 Sample Autocorrelation of a Time Series

Online Cumulative Bollinger Bands: Welford-Recurrence Band-Pair Stream

Online EWMA Covariance Pair — Cross-Asset Hedge-Ratio Building Block

Online EWMA Residual Stream — Surprise-vs-Prior Exponential-Weight Mean

Online EWMA Variance — Recency-Weighted Volatility Tracker

Running Mean and Mean Absolute Deviation

Online Median of Slippage

Online Running Excess Kurtosis via Welford-Style Fourth-Moment Recurrence

Online Running Sample Skewness via Welford-Style Third-Moment Recurrence

Online Streaming Mean, Variance, Skewness, and Excess Kurtosis (Welford-Pebay)

Online Z-Score Outlier Flagger: Welford-Cumulative Anomaly Detection on a Tick Stream

Optimal Cooldown Period Trades

Optimal Strike Allocation in Option Spread

Order Queue Priority

Router Reliability Check: Count Orphan Cancellations

Pancake Sort: Flip Sequence

Parallel Pairwise Mean Merge with Kahan Compensation

Partition Orders to Minimize Basis Mismatch

Pascal's Triangle Row in O(k) Space

Peak Inventory Day After Batched Range-Update Trades

Quantile Estimate from Pre-Bucketed Histogram Counts

Linear-Interpolation Percentile of Trade PnL

Cache-Aware Pipeline Replay — Minimum Re-run Set with Input-Hash Chaining

Research Pipeline DAG — Cascade-Invalidate Downstream of a Failed Task

Research Pipeline DAG — Compute the Next-Runnable Set

Aggregate P&L Up a Portfolio Hierarchy Tree

Whole-Share Portfolio Allocator under a Single-Name Cap

Position Fingerprint Grouping

Power-of-Two Bit Check

Prev-Stronger Bid Distance: Time Since the Last Strictly-Higher Bid Print

Primality Test by Trial Division

Priority-Driven Task Scheduling with Deps on a Worker Pool

Probability of Reaching a Target Leaf Set on a Binary Scenario Tree

Quartile Pack with IQR from Per-Period Returns

2D Range Sum via Prefix Table

Rank Records by Multi-Key Tie-Break Rule

Rank-Disagreement Count: Pairwise Inversions Between Expected and Realized Strategy Rankings

Rank Strategies by Sharpe with Vol Tiebreak

Realign K Trade Tapes to a Global Clock with Per-Tape Offsets

Forward Recovery Distance: Days Until Cumulative Gain Clears Delta

Recursive Walk Down a Hierarchical Rebate-Tier Tree

Per-Node Conditional Expected Leaf Payoff on a Scenario Tree

Regime Transition Path Count: Modular DAG Walk Enumeration with Distinguishable Catalysts

Removing K Digits — Smallest Result

Reverse String

First-Update-After-Stale-Period Flags on a Quote-Update Timestamp Stream

Live Trade-Rate Count over a Half-Open Lookback Sliding Window

Longest Stable-Volatility Regime via Rolling Sample-Stddev Sliding Window

Minute-Bar Range Monitor via Dual-Deque Sliding Max-Minus-Min

Roman Numeral to Integer

Rotting Oranges — Multi-Source BFS

Running Cumulative Sum over a Stream

Counterparty Diversity Diagnostic: Running Distinct Counterparty Count

Running Maximum Drawdown of a Streamed Log-Return NAV Path

Running Min and Max of a Stream

Running Cumulative-History Pearson Correlation via Welford-Style Co-Moment Recurrence

P-Square (P²) Streaming Quantile Estimator

Running Unbroken-Bid Stack Sum: Cumulative Support of Still-Standing Prior Bids

Expected PnL on a Risk-Officer Scenario Tree

Worst-Case Leaf PnL on a Risk-Officer Scenario Tree

Sector-Day Return Cube: Batched Rectangular Range Sums

Session-Window Aggregation — Gap-Driven Boundaries

Shortest Hop Path on a Routing Graph

Shortest Contiguous Window Whose Absolute-Return Sum First Reaches a Stress-Budget Target

Shortest Window Hitting a Cumulative Return Target

Shortest Window Containing K Magnitude Spikes in a Return Stream

Size-Weighted Median Fill Price

Sliding Window Max of Quotes

Sliding-Window Mean — Fixed-Count Window with O(1) Eviction

Sliding-Log Rate Limiter (Deque of Admitted Timestamps)

Smallest Position Size Meeting Risk Budget

Span of Higher Highs

Sticky Binary-State Strategy — Best PnL With Per-Flip Tax And Initial-State Anchor

Online Stock Span

Per-Strategy P&L Bookkeeping with Mark-to-Market

Strategy Leaderboard: Top-K by Sharpe with Lexicographic Tie-Break

Stream Running Distinct Count

Streaming K-th Largest P&L

Running VWAP Across Merged K-Venue Trade Tapes

Streaming Median Over a Fixed Time Window

Streaming Running Mode — Most-Frequent Value with Lazy-Deletion Heap

Streaming Top-K Tickers by Notional

Reverse Words in a Sentence

Valid Palindrome (Alphanumeric, Case-Insensitive)

Total Uniform-Fill Shares across Every Order-Book Level Range

Subarray Sum Equals K

Subranges Above Return Threshold

Aggregate Bottleneck Bid-Depth across All Contiguous Price-Band Sweeps (Depth-Uniformity Score)

Sum of Subarray Minimum P&Ls

T-Digest Streaming Percentile Estimator (k_1 Scale Function)

Three-Stream Synchronized Triple Count Within Tolerance

Tick Buffer — Binary-Search Lookup and Range Scan by Timestamp

Token-Bucket Rate Limiter with Bounded Pending Queue

Top K Liquid Tickers

Top K PnL Days So Far

TCA Worst-K Fills: Top-K Slippage with Stable Arrival-Seq Tiebreak

Co-Trading Graph — Connected Components of Session Trade Pairs

Aggregate a Trade Tape Into Per-Bucket OHLCV Bars

Trailing High-Watermark Span: Per-Tick Consolidation Length on a Synthetic Tape

Trapping Volume Between Local-Max Quotes

Tree Reduction with (min, max) Associative Combiner

Search a Binary Search Tree for a Target

Iterative Tribonacci Number

Tumbling-Window Aggregation — Sparse Per-Bucket Stats

Two-Budget Strike-Premium Knapsack (Delta and Vega Caps)

Two Sum

Unique Paths with Obstacles

Unique Tickers In Session

Valid Anagram (Character Counts)

Validate Binary Search Tree (Recursive Bounds)

Watermark-Driven Tumbling Windows with Late-Event Handling

Weighted-Cost Edit Distance Between Trade-Action Paths

Welford Warm-up-Trimmed Sample Variance — Stable Online Estimator on a Trailing Tail

Sliding-Window Argmin Offset: Per-Window Position of the Minimum Price Relative to the Window Left Edge

Tumbling Window Trigger Firing Policies (Early, On-Close, Speculative)

Rolling Hit-Rate of Strictly-Positive Returns over a Fixed-Size Window