代码题库

Add Two Binary Strings

Array Product Except Self

Best Single Trade in a Day

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

Per-Position Flag Bitmask Queries

Trade-Size Tier Histogram via Right-Inclusive Edges

Bucket-Sort P&L Histogram

Canonical Ticker-Symbol Form — Cross-Venue Dedup

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

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

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

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

Cumulative Volume Snapshot

Days Until a Better PnL

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

Recursive Binary Decision-Tree Evaluator

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

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

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

First Unique Character

FizzBuzz

GCD of Share Lots — Round-Lot Reconciliation

Count Connected Components in an Undirected Graph

Detect a Cycle in an Undirected Graph

Greedy Coin Change on a Canonical Denomination Set

Minimum Platforms for a Railway Schedule

Minimum Cost Path Through a Grid

Maximum P&L Path Through a Grid

Jump Game — Can You Reach the Last Index

K-Day Rolling Mean Filter

Minimum Eating Speed (Binary Search on the Answer)

Largest Divisible Pair (Sort + Scan)

Longest Palindromic Substring

Longest Substring Without Repeating Characters

Match Bid and Ask Snapshots

Max Non-Overlapping Trade Windows

Max Sum of Fixed-Size Window

Merge Overlapping Quote-Validity Windows

Merge Two Sorted Lists — Iterative Two-Pointer

Min Cash Buffer to Survive

Minimum Flips for Monotone Up-Day Pattern

Minimum Concurrent Streaming Jobs for Execution Windows

Min-Stack with O(1) get_min

Minimum Tickers for Liquidity Coverage

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

Next Greater Quote Timestamp

Next Smaller Element Index

Min Rebalance Windows To Remove

Min Intervals To Remove For Non-Overlap

Lag-1 Sample Autocorrelation of a Time Series

Running Mean and Mean Absolute Deviation

Pascal's Triangle Row in O(k) Space

Peak Inventory Day After Batched Range-Update Trades

Aggregate P&L Up a Portfolio Hierarchy Tree

Power-of-Two Bit Check

Primality Test by Trial Division

2D Range Sum via Prefix Table

Rank Records by Multi-Key Tie-Break Rule

Recursive Walk Down a Hierarchical Rebate-Tier Tree

Reverse String

Roman Numeral to Integer

Rotting Oranges — Multi-Source BFS

Running Cumulative Sum over a Stream

Running Min and Max of a Stream

Shortest Hop Path on a Routing Graph

Stream Running Distinct Count

Streaming K-th Largest P&L

Reverse Words in a Sentence

Valid Palindrome (Alphanumeric, Case-Insensitive)

Top K Liquid Tickers

Search a Binary Search Tree for a Target

Iterative Tribonacci Number

Two Sum

Unique Paths with Obstacles

Unique Tickers In Session

Valid Anagram (Character Counts)

Validate Binary Search Tree (Recursive Bounds)