主页
2022/12/02
Hackerrank - DigitalWallet
2022/12/01
RuntimeException and checked Exception
2022/12/01
347. Top K Frequent Elements
2022/12/01
380. Insert Delete GetRandom O(1)
2022/11/29
1094. Car Pooling
2022/11/24
Setup Zookeeper + Kafka in VMware
2022/11/20
543. Diameter of Binary Tree
2022/11/19
1628. Design an Expression Tree With Evaluate Function
2022/11/19
1152. Analyze User Website Visit Pattern
2022/11/17
364. Nested List Weight Sum II
2022/11/17
339. Nested List Weight Sum
2022/11/17
277. Find the Celebrity
2022/11/17
1429. First Unique Number
2022/11/17
510. Inorder Successor in BST II
2022/11/17
285. Inorder Successor in BST
2022/11/15
System design cheat sheet
2022/11/14
472. Concatenated Words
2022/11/14
207. Course Schedule
2022/11/14
695. Max Area of Island
2022/11/14
987. Vertical Order Traversal of a Binary Tree
2022/11/14
653. Two Sum IV - Input is a BST
2022/11/14
1046. Last Stone Weight
2022/11/14
1160. Find Words That Can Be Formed by Characters
2022/11/14
Google questions
2022/11/13
803. Bricks Falling When Hit
2022/11/13
2402. Meeting Rooms III
2022/11/11
683. K Empty Slots
2022/11/11
359. Logger Rate Limiter
2022/11/11
681. Next Closest Time
2022/11/11
545. Boundary of Binary Tree
2022/11/11
430. Flatten a Multilevel Doubly Linked List
2022/11/08
2221. Find Triangular Sum of an Array
2022/11/08
1567. Maximum Length of Subarray With Positive Product
2022/11/08
2104. Sum of Subarray Ranges
2022/11/08
719. Find K-th Smallest Pair Distance
2022/11/08
2259. Remove Digit From Number to Maximize Result
2022/11/08
1710. Maximum Units on a Truck
2022/11/08
2006. Count Number of Pairs With Absolute Difference K
2022/11/08
TODO
2022/11/08
244. Shortest Word Distance II
2022/11/04
727. Minimum Window Subsequence
2022/11/04
1740. Find Distance in a Binary Tree
2022/11/04
269. Alien Dictionary
2022/11/04
366. Find Leaves of Binary Tree
2022/11/04
253. Meeting Rooms II
2022/11/04
250. Count Univalue Subtrees
2022/11/01
937. Reorder Data in Log Files
2022/11/01
994. Rotting Oranges
2022/10/31
1662. Check If Two String Arrays are Equivalent
2022/10/31
710. Random Pick with Blacklist
2022/10/30
Redis (NoSQL) Cache
2022/10/30
1366. Rank Teams by Votes
2022/10/29
MySql (4) - Performance Optimization
2022/10/29
Java Design Pattern
2022/10/29
224. Basic Calculator
2022/10/27
MySql (1) - Indexing, Locking and Transaction
2022/10/27
MySql (3) - Sharding
2022/10/27
2290. Minimum Obstacle Removal to Reach Corner
2022/10/26
MySql (2) - Master/slave
2022/10/26
MyBatis and SSM (Spring/SpringMVC/MyBatis)
2022/10/25
SpringMVC learning notes
2022/10/25
Java Spring framework
2022/10/24
463. Island Perimeter
2022/10/24
1254. Number of Closed Islands
2022/10/24
547. Number of Provinces
2022/10/24
1864. Minimum Number of Swaps to Make the Binary String Alternating
2022/10/24
1854. Maximum Population Year
2022/10/24
655. Print Binary Tree
2022/10/23
202. Happy Number
2022/10/23
948. Bag of Tokens
2022/10/23
234. Palindrome Linked List
2022/10/22
662. Maximum Width of Binary Tree
2022/10/22
426. Convert Binary Search Tree to Sorted Doubly Linked List
2022/10/22
523. Continuous Subarray Sum
2022/10/20
875. Koko Eating Bananas
2022/10/20
276. Paint Fence
2022/10/20
158. Read N Characters Given read4 II - Call Multiple Times
2022/10/20
Java一些基础语法：Comparator, MapEntry, Iterator
2022/10/19
440. K-th Smallest in Lexicographical Order
2022/10/19
241. Different Ways to Add Parentheses
2022/10/18
17.12. BiNode LCCI
2022/10/17
并查集 (261. Graph Valid Tree)
2022/10/17
261. Graph Valid Tree
2022/10/17
622. Design Circular Queue
2022/10/17
773. Sliding Puzzle
2022/10/17
240. Search a 2D Matrix II
2022/10/17
238. Product of Array Except Self
2022/10/16
1249. Minimum Remove to Make Valid Parentheses
2022/10/16
394. Decode String
2022/10/16
331. Verify Preorder Serialization of a Binary Tree
2022/10/16
993. Cousins in Binary Tree
2022/10/16
1352. Product of the Last K Numbers
2022/10/16
2096. Step-By-Step Directions From a Binary Tree Node to Another
2022/10/16
311. Sparse Matrix Multiplication
2022/10/15
981. Time Based Key-Value Store
2022/10/15
1123. Lowest Common Ancestor of Deepest Leaves
2022/10/15
236. Lowest Common Ancestor of a Binary Tree
2022/10/15
1769. Minimum Number of Operations to Move All Balls to Each Box
2022/10/15
1302. Deepest Leaves Sum
2022/10/15
1712. Ways to Split Array Into Three Subarrays
2022/10/15
1326. Minimum Number of Taps to Open to Water a Garden
2022/10/14
221. Maximal Square
2022/10/14
295. Find Median from Data Stream
2022/10/14
739. Daily Temperatures
2022/10/13
System design questions
2022/10/12
163. Missing Ranges
2022/10/12
222. Count Complete Tree Nodes
2022/10/12
210. Course Schedule II
2022/10/11
1428. Leftmost Column with at Least a One
2022/10/11
1143. Longest Common Subsequence
2022/10/11
785. Is Graph Bipartite?
2022/10/11
692. Top K Frequent Words
2022/10/10
417. Pacific Atlantic Water Flow
2022/10/10
983. Minimum Cost For Tickets
2022/10/10
769. Max Chunks To Make Sorted
2022/10/10
239. Sliding Window Maximum
2022/10/10
652. Find Duplicate Subtrees
2022/10/09
696. Count Binary Substrings
2022/10/09
299. Bulls and Cows
2022/10/08
396. Rotate Function
2022/10/08
1654. Minimum Jumps to Reach Home
2022/10/08
206. Reverse Linked List
2022/10/06
264. Ugly Number II
2022/10/05
797. All Paths From Source to Target
2022/10/05
1405. Longest Happy String
2022/10/02
1423. Maximum Points You Can Obtain from Cards
2022/09/26
1153. String Transforms Into Another String
2022/09/25
642. Design Search Autocomplete System
2022/09/23
1652. Defuse the Bomb
2022/09/23
346. Moving Average from Data Stream
2022/09/23
418. Sentence Screen Fitting
2022/09/23
340. Longest Substring with At Most K Distinct Characters
2017/05/21
[Question] Trie Wildcard String Matching
2017/05/12
[Question] Dutch national flag problem
2016/07/31
[Design] How to Design Logging
2016/07/30
[Design] MVC, MVP and MVVM
2016/07/10
[Design] Design Twitter
2016/06/10
[Octopress] Add Aside Content to Octopress
2016/05/07
[Design] User Registry Table Design
2015/11/21
[Design] Designing a simple web crawler
2015/11/20
[Design] How to generate Maze
2015/11/20
[Question] Swizzle Sort
2015/11/17
[Design] Strategy design pattern
2015/11/14
[Question] Partition Problem (divide array into halves)
2015/11/03
[LeetCode 188] Best Time to Buy and Sell Stock IV
2015/10/27
[Java OOP] Java ArrayList implementation
2015/10/22
[Java OOP] Template method pattern (abstract class)
2015/10/22
[Java OOP] What is Java Exception
2015/10/22
[Java OOP] Java Vector and ArrayList
2015/10/22
[Java OOP] Static class and Inner class
2015/10/21
[Java OOP] Why avoid using Protected?
2015/10/21
[Fundamental] What is a Literal?
2015/10/21
[Fundamental] Reflexive, Symmetric and Transitive Rules
2015/10/21
[Fundamental] Polynomial, quadratic, cubic and exponential
2015/10/13
[Fundamental] UML Class Diagrams
2015/10/12
[LintCode] Segment Tree Build II
2015/10/12
[LintCode] Segment Tree Build
2015/10/12
[LintCode] Segment Tree Modify
2015/10/12
[LintCode] Segment Tree Query II
2015/10/12
[LintCode] Segment Tree Query
2015/10/07
[Fundamental] Segment Tree
2015/10/06
[Amazon] All Strings by Placing Spaces
2015/10/06
[Question] Find Cloest Leaf in Binary Tree
2015/10/06
[Question] Largest Sub-square with Edges filled
2015/10/03
[Fundamental] The 7 Bridges Problem
2015/10/01
[Google] Shortest Manhattan Distance
2015/09/01
[Design] Facebook Photo Storage
2015/08/29
[Design] How Google search works
2015/08/29
[NineChap System Design] Class 4.1: Crawler
2015/08/29
[NineChap System Design] Class 4.2: Search Engine
2015/08/27
[NineChap System Design] Class 3.2: Web Service
2015/08/27
[NineChap System Design] Class 3.1: Web Service
2015/08/25
[NineChap System Design] Class 2.1: Database
2015/08/25
[NineChap System Design] Class 2.2: Database
2015/08/23
[Java OOP] Three Properties of Class/Object
2015/08/22
[NineChap System Design] Class 1.1: Overview
2015/08/22
[NineChap System Design] Class 1.2: An Example
2015/08/22
[NineChap System Design] Class 1.3: Improvement
2015/07/22
[Design] How is Pipe implemented in Unix/Linux
2015/06/08
[Design] Cryptographic standard, AES and RSA
2015/06/07
[Design] Linux and TCP ports
2015/05/23
[Java OOP] Overload, Override, Compile, Runtime (Static/Dynamic Polymph)
2015/05/20
[Palantir] Sort Letters Given Lexicographic Order
2015/05/09
[LeetCode 201] Bitwise AND of Numbers Range
2015/05/09
[LeetCode 191] Number of 1 Bits
2015/05/09
[LeetCode 200] Number of Islands
2015/05/09
[LeetCode 198] House Robber
2015/05/09
[LeetCode 189] Rotate Array
2015/05/09
[LeetCode 199] Binary Tree Right Side View
2015/05/09
[LeetCode 190] Reverse Bits
2015/04/30
[LeetCode 187] Repeated DNA Sequences
2015/04/14
[LeetCode 173] Binary Search Tree Iterator
2015/04/14
[LeetCode 174] Dungeon Game
2015/04/14
[LeetCode 179] Largest Number
2015/04/13
[LeetCode 168] Excel Sheet Column Title
2015/04/13
[LeetCode 169] Majority Element
2015/04/13
[UVa] Wooden Sticks
2015/04/13
[Question] 编程之美 NIM 一排石头的游戏
2015/04/12
[LeetCode 172] Factorial Trailing Zeroes
2015/04/12
[LeetCode 171] Excel Sheet Column Number
2015/04/12
[LeetCode 164] Maximum Gap
2015/04/11
[LeetCode 165] Compare Version Numbers
2015/04/11
[LeetCode 162] Find Peak Element
2015/04/11
[Palantir] Find Duplicate within K Distance
2015/04/11
[Palantir] MultiMap in Java without using Collections
2015/04/10
[LeetCode 166] Fraction to Recurring Decimal
2015/04/07
[LeetCode 160] Intersection of Two Linked Lists
2015/04/06
[LeetCode 154] Find Minimum in Rotated Sorted Array II
2015/04/06
[LeetCode 153] Find Minimum in Rotated Sorted Array
2015/04/06
[LeetCode 155] Min Stack
2015/04/06
[Octopress] Add Google AdSense to Octopress
2015/04/06
[LeetCode 152] Maximum Product Subarray
2015/02/14
[Design] HBase and HDFS
2015/02/13
[Design] Speed Up Webpage for Slow Connection (1)
2015/02/13
[Design] Speed Up Webpage for Slow Connection (2)
2015/02/13
[Design] Speed Up Webpage for Slow Connection (3)
2015/02/13
[Design] Speed Up Webpage for Slow Connection (4)
2015/02/12
[LinkedIn] Sum of integer weighted by depth
2015/02/12
[LinkedIn] Unique combination of factors (因式分解)
2015/02/12
[LinkedIn] Sort part to make entire array sorted
2015/02/12
[Google] Minimum adjustments
2015/02/11
[LinkedIn] Executive's Schedule
2015/02/10
[LinkedIn] Isomorphic Strings
2015/02/10
[Design] Application Server vs. Web Server
2015/02/09
[Design] Design Cache System (`)
2015/02/08
[Google] Array Signature
2015/02/08
[Java OOP] Can abstract class have constructor
2015/02/08
[Java OOP] Can abstract class have 0 abstract method?
2015/02/08
[Question] Count multiples of array
2015/02/08
[Google] Heap and BST conversion
2015/02/08
[Design] Intro to Google Spanner
2015/02/08
[Google] Number of slices
2015/02/07
[Design] Big Data - Find Common Elements in 2 Lists
2015/02/07
[Design] Difference: Internet and the Web
2015/02/07
[Google] BST find ceiling
2015/02/07
[Facebook] Generate number with Given probability
2015/02/07
[Design] Find similar library books
2015/02/07
[Google] Transform a unbalanced tree into balanced tree
2015/02/07
[Google] Transform a unbalanced tree into balanced tree
2015/02/06
[Question] Check string with no common letters (Bitmask)
2015/02/06
[Google] First Unique URL
2015/02/06
[Google] Max prodcut of strings that have no common char
2015/02/06
[Design] Multithreading Async Increment Problem
2015/02/06
[Question] Reservoir sampling
2015/02/06
[Google] Continental divider
2015/02/04
[Google] Multi-server Messaging System
2015/02/04
[Java OOP] PubSub (Publish–subscribe) pattern
2015/02/04
[Google] Set Cover Problem
2015/02/04
[Google] Implement a Blocking Queue
2015/02/04
[Design] Winning Games Rank (pagerank)
2015/02/03
[Google] Data Structure of Insert, Remove, GetRandom
2015/02/03
[Amazon] Grep command interview question
2015/02/03
[Google] Number of subtrees with even nodes
2015/02/03
[Google] Collatz Conjecture (Oneness property)
2015/02/03
[Google] Snakes and ladders
2015/02/02
[Design] Monitor Rps for Past sec/min/hr
2015/01/31
[Greedy] Activity Selection Problem
2015/01/31
[Design] Limit the Request per Second
2015/01/31
[Greedy] Each Employee 2 events
2015/01/31
[Question] Stock Span Problem (couting BST)
2015/01/29
[Question] 2D Bin Packing
2015/01/28
[Apple] Calculate Area
2015/01/28
[Question] Packing Rectangles
2015/01/28
[Question] Product Array Puzzle
2015/01/27
[Fundamental] Implement Trie and Suffix Tree
2015/01/27
[Question] Two Dimensional Knapsack Problem
2015/01/26
[Google] Generate Request ID
2015/01/26
[Fundamental] Pattern Searching Algorithms
2015/01/26
[Fundamental] Prefix Tree
2015/01/26
[Fundamental] Suffix Array
2015/01/26
[Fundamental] Suffix Tree
2015/01/25
[Question] Push and Pop Sequences of Stacks
2015/01/25
[Google] Make a Java method thread-safe
2015/01/23
[Design] Design Google Suggest (autocomplete)
2015/01/23
[Design] Distributed Caching - memcached
2015/01/19
[Palantir] Largest basin size in matrix
2015/01/19
[Google] Top n values from Sum of 2 arrays
2015/01/19
[Java OOP] Java Vector and ArrayList
2015/01/19
[Java OOP] Interface and Abstract classes
2015/01/19
[Design] Difference between HTTP and HTTPS
2015/01/18
[Question] Check if two line segments intersect
2015/01/18
[Design] Difference between HTTP protocol and TCP protocol
2015/01/18
[Question] Check if given point inside polygon
2015/01/17
[Amazon] Lexicographic rank of a string
2015/01/17
[Google] Lexicographic order (letter replacement) of dictionary
2015/01/17
[Question] Maximum square sub-matrix with all 1s
2015/01/16
[Amazon] Find nodes of distance k from Binary Tree
2015/01/11
[Java OOP] BlockingQueue and Thread Pool
2015/01/11
[Java OOP] Java BlockingQueue (2)
2015/01/11
[Java OOP] Java BlockingQueue (1)
2015/01/10
[Google] Diameter of a Binary Tree
2015/01/10
[Question] All distinct subsequences with given length
2015/01/10
[LinkedIn] Find all repeating substring with given length
2015/01/10
[Google] Check if repeating subsequence exists
2015/01/10
[Google] Crazy Distance Between Strings
2015/01/10
[Amazon] Longest Repeating Substring
2015/01/10
[Question] Number of distinct sub-sequence
2015/01/10
[Question] Number of occurence of given sub-sequence
2015/01/09
[Google] Form a Queue Given Heights
2015/01/09
[Google] Maximum Count Array in a Queue
2015/01/09
[Google] Reverse a Stack without DS
2015/01/09
[Amazon] Mininum Range that includes at least One
2015/01/08
[Design] Real Time Top k
2015/01/08
[Design] Big Data - Top k Frequency (hands-on)
2015/01/08
[Question] Most Frequent Word from a book
2015/01/08
[Amazon] Match triplet with reverse order
2015/01/08
[Design] Terminology: n-gram
2015/01/07
[Google] Check all numbers given the decimal scale
2015/01/07
[Google] Number of distinct substrings
2015/01/06
[Design] P2P Technology
2015/01/06
[Question] Longest Common Substring
2015/01/06
[Facebook] Scheduling Jobs with Max Cost
2015/01/05
[Design] Big Data Storage
2015/01/05
[Design] Cloud, Grid and Cluster
2015/01/05
[Design] Distributed hash table
2015/01/05
[Facebook] Write a Json prettifier
2015/01/01
[Question] Frog Crossing (dynamic programming)
2014/12/26
[Design] Database Indexing
2014/12/22
[Ruby] Endless error with gem dependencies
2014/12/22
[Java OOP] Java Runtime Exception
2014/12/21
[Java OOP] Discussion of Polymorphism
2014/12/21
[Facebook] Maximum sum such that no two elements are adjacent
2014/12/21
[Ruby] RubyGems, gem, Gemfile and Bundler
2014/12/21
[Question] Split an integer or coin
2014/12/21
[Java OOP] Interface extend another Interface
2014/12/21
[Java OOP] Common Root of Java Classes
2014/12/21
[Java OOP] Override/overload Java main method
2014/12/17
[Facebook] Binary Search Tree 3Sum
2014/12/16
[Question] Equilibrium Points in 2D Array
2014/12/16
[Facebook] Print a Binary Tree in Vertical Order
2014/12/07
[Epic] Patient Disease Data Structure
2014/12/01
[Question] Axis Aligned Rectangles
2014/11/29
[Question] Multiples of 3 and 5
2014/11/03
[Google] Code a HashMap
2014/10/31
[Question] Find row with most 1s
2014/10/07
[Question] Interleave Positive and Negative Numbers
2014/10/01
[CC150v5] 18.7 Longest Word Made From Other Words
2014/09/30
[CC150v5] 17.14 Optimal Way to Unconcatenate Doc
2014/09/29
[CC150v5] 17.13 Convert BST to DLL
2014/09/27
[CC150v5] 11.8 Get Rank in Stream of Integers
2014/09/26
[CC150v5] 17.6 Order an Array by Sorting Middle
2014/09/25
[CC150v5] 14.6 Implement CircularArray in Java
2014/09/23
[CC150v5] 12.0 Example - Troubleshoot Google Chrome
2014/09/23
[CC150v5] 11.4 Sort 20GB File
2014/09/16
[CC150v5] 9.7 Paint Fill in Map
2014/09/16
[CC150v5] 9.10 Stack up the Boxes
2014/09/16
[CC150v5] 9.3 Find Magic Index
2014/09/16
[CC150v5] 9.11 Parenthesize the Expression
2014/09/15
[CC150v5] 5.1 Binary Merge 2 Numbers
2014/09/15
[Brain teaser] 6.1 Bottles of Pills
2014/09/15
[Google] Guess Password
2014/09/15
[CC150v5] 5.6 Swap Odd and Even Bits
2014/09/15
[CC150v5] 5.5 Calculate Bits Conversion Required
2014/09/14
[CC150v5] 3.0 Example - Implement Stack
2014/09/14
[CC150v5] 2.7 Linked List Palindrome
2014/09/14
[CC150v5] 3.2 Stack Min Value
2014/09/14
[CC150v5] 3.7 Stack of Animals
2014/09/13
[CC150v5] 2.2 Kth last element (recursive)
2014/09/11
[Design] DNS Communication Protocol
2014/09/10
[Google] Length of Longest Arithmetic Progression (LLAP)
2014/09/10
[Google] Arithmetic Progression Triplet
2014/09/10
[Google] Barrier, Goods Van and Distance
2014/09/10
[Question] Celebrity Problem
2014/09/09
[CC150v4] 20.4 Count 2s in Digits
2014/09/09
[CC150v4] 20.8 Full Text Search (suffix tree)
2014/09/09
[CC150v4] 20.11 Find Subsquare with Black Border
2014/09/09
[CC150v4] 20.12 Sub-matrix with Largest Sum
2014/09/09
[CC150v4] 20.3 Generate M int from Array of Size N
2014/09/09
[CC150v4] 20.6 Top Million from Billion
2014/09/08
[CC150v4] 19.6 Convert Integer to English
2014/09/08
[Google] Winner of tic-tac-toe
2014/09/08
[CC150v4] 19.4 Get Max Number without Comparator
2014/09/07
[CC150v4] 10.6 Find Collinear in 2D Plane
2014/09/07
[CC150v4] 10.4 Implement Mathematical Operators
2014/09/07
[CC150v4] 14.3 Java Final, Finally and Finalize
2014/09/07
[CC150v4] 14.6 Java HashMap Counter
2014/09/07
[CC150v4] 14.2 Java Finally Statement
2014/09/07
[CC150v4] 11.2 Random error debugging 2
2014/09/07
[CC150v4] 14.1 Java Private Constructor
2014/09/07
[CC150v4] 15.1 SQL count and group by statement
2014/09/07
[CC150v4] 14.5 Java Reflection
2014/09/07
[CC150v4] 15.2 SQL Types of Join
2014/09/07
[CC150v4] 11.4 Test Webpage without Tools
2014/09/06
[CC150v4] 5.2 Convert Integer to Binary Form
2014/09/06
[Brain teaser] 6.2 Cover the Chess Board
2014/09/06
[CC150v4] 5.7 Find Missing Number
2014/09/06
[CC150v4] 8.4 Generate Permutation Recursively
2014/09/06
[CC150v4] 9.5 Search Array Containing Empty String
2014/09/06
[CC150v4] 9.0 Example - Sort Persons
2014/09/05
[CC150v4] 4.7 Check Subtree
2014/09/05
[CC150v4] 4.5 Find Next Node in BST
2014/09/05
[CC150v4] 3.4 Towers of Hanoi
2014/09/05
[CC150v4] 4.8 Print Path Sum to Value
2014/09/05
[Google] Form a Palindrome with Insertion
2014/09/05
[CC150v4] 3.6 Sort Stack
2014/09/03
[Google] Find Second Shortest Path
2014/09/03
[Google] Unsolved Mystery of UTF8 Encoding
2014/09/02
[Design] Leader Election
2014/09/02
[Google] String Replacement Question
2014/09/02
[Google] Weird Sort Array
2014/09/01
[Google] Array Distance A(i)+A(j)+(j-i)
2014/09/01
[Google] Find Anagrams in Dictionary
2014/09/01
[Java OOP] Observer pattern
2014/08/31
[Google] Crosswod Solver
2014/08/31
[Design] Multithreading - Deadlock Prevention
2014/08/31
[Facebook] Hamming Distance of Array
2014/08/29
[Fundamental] A-Star Search
2014/08/29
[Fundamental] Min-Max Algorithm (minmax)
2014/08/29
[Design] Cryptographic Hash, MD5 and Digital signature
2014/08/29
[Fundamental] Travelling salesman problem
2014/08/28
[Google] Boggle Solver (search words from matrix)
2014/08/27
[Design] HTTP cookie
2014/08/27
[Google] Google Pre-interview Coaching
2014/08/27
[CC150v4] 10.7 Ugly Numbers (Hamming numbers)
2014/08/26
[Twitter] Count Visible Nodes in Binary Tree
2014/08/26
[Question] Duplicate Rows in Matrix
2014/08/26
[Google] Google API read4096 (read4K)
2014/08/26
[Twitter] Largest Cycle in Permutation
2014/08/25
[Testing] Test hashCode() function
2014/08/25
[Design] Virtual Memory, Page Fault and Thrashing
2014/08/25
[Design] OOD Design of Elevator
2014/08/24
[CC150v5] 8.10 Implement a Hashmap
2014/08/24
[CC150v5] 8.9 Design a in-memory File System
2014/08/24
[CC150v5] 8.4 Design a Parking Lot
2014/08/23
[CC150v5] 8.7 Design Online Chat Server (1)
2014/08/23
[CC150v5] 8.8 Design Othello Game
2014/08/23
[CC150v5] 8.7 Design Online Chat Server (2)
2014/08/22
[Design] Stack and Heap
2014/08/22
[Design] Shared Hosting vs. VPS Hosting
2014/08/22
[Design] Merits of BST over HashTables
2014/08/21
[CC150v5] 8.1 Design a Generic Deck of Cards
2014/08/19
[Question] Count Set Bit in Binary Number
2014/08/19
[Question] Ways of Dice Throw
2014/08/19
[Question] Square Count of Matchstick Graph
2014/08/19
[Java OOP] Singleton, 3 implementations
2014/08/18
[Question] Count Level in Perfect Binary Tree
2014/08/18
[Java OOP] Factory Pattern
2014/08/18
[Java OOP] Singleton Pattern Introduction
2014/08/16
[ItInt5] Number of Valid Trees Given Preorder and Postorder
2014/08/16
[Twitter] Arithmetic Expression Evaluation
2014/08/16
[ItInt5] Numbers Concatenation Max (Largest Number)
2014/08/15
[Google] Orthogonal Traverse the Map (`)
2014/08/15
[ItInt5] Excel Decimal Conversion
2014/08/14
[Google] Alphabet Table (`)
2014/08/14
[Google] Product All 1s
2014/08/14
[ItInt5] 跳马问题加强版
2014/08/14
[Facebook] Task Scheduling Question
2014/08/14
[Question] Greatest Common Divisor
2014/08/13
[Facebook] Query Search (HashMap, suffix array)
2014/08/11
[Design] From Client/Server to Multi-Tier
2014/08/11
[CC150v4] 9.7 Circus Tower Routine
2014/08/10
[Design] TCP 3-Way Handshake
2014/08/10
[Google] Count Complete Binary Tree
2014/08/10
[ItInt5] Maximum circular subarray sum
2014/08/09
[Design] Big Data - Remove Duplicate Numbers
2014/08/09
[Design] Big Data - Top k Frequency (case analysis)
2014/08/09
[Design] Big Data - Find Existence of a Number
2014/08/09
[Design] Big Data - Fuzzy Search url (Bloom Filter)
2014/08/09
[Design] Big Data - Find Median Numbers
2014/08/08
[Design] Median of array in Distributed Computers
2014/08/08
[Design] Functional programming
2014/08/08
[Testing] Test Command Line Copy
2014/08/08
[Design] Process VS. Thread
2014/08/07
[Question] Add Integers without +/++
2014/08/07
[Question] Decimal to Hexadecimal
2014/08/07
[Design] Composition Over Inheritance
2014/08/07
[Question] Max Sum Of Non-Consecutive Elements
2014/08/07
[Design] Producer Consumer Problem
2014/08/07
[Java OOP] Thread pool pattern
2014/08/06
[Google] Million Phone Numbers
2014/08/06
[Testing] Random error debugging 1
2014/08/06
[CC150v4] 9.4 Sort Large Files
2014/08/06
[Design] Distributed Network Bottleneck
2014/08/05
[Google] Connect Graph Nodes and Avoid Intersect
2014/08/05
[Design] HTTP Headers
2014/08/05
[Design] Networks and TCP/IP
2014/08/05
[Google] Postorder successor in Binary Tree
2014/08/04
[Design] Amazon Web Services
2014/08/04
[Design] MapReduce Common Friends Example
2014/08/04
[Design] MapReduce Intro
2014/08/04
[Google] Replace Question Mark With Number
2014/08/04
[Java OOP] Upcasting, Downcasting and Object Slicing
2014/08/04
[Question] Print Numbers containing 5
2014/08/04
[Google] Write a Random Number Generator
2014/08/03
[Google] Find Nearest Point in a 2D Space
2014/08/03
[Google] Find Occurance Greater Than Index
2014/08/03
[Google] Traveller Path Problem
2014/08/03
[Design] Overview of Big Data Technology
2014/08/03
[Design] Hadoop cluster
2014/08/03
[Design] Model–view–controller (MVC)
2014/08/02
[Google] Design Solar System (`)
2014/08/02
[Design] Multilayered architecture
2014/08/02
[Google] Three Keys Data Structure
2014/08/02
[CC150v4] 17.1 Type a URL in Browser and Hit Enter
2014/08/01
[Google] Print string comparison order
2014/08/01
[Google] Special increasing adjacent sequence
2014/07/31
[Question] Arranging Sequence
2014/07/31
[Question] Overriding private method
2014/07/31
[Question] Shuffle An Array (Fisher–Yates)
2014/07/31
[Question] Max Sum In A 2D Array (sub-matrix)
2014/07/30
[Question] Inorder Successor in Binary Search Tree
2014/07/30
[Question] Points On Globe Puzzle
2014/07/30
[Question] Run-Length Encoding
2014/07/29
[Question] Nth Fibonacci Number In O(LogN)
2014/07/29
[Question] Peripheral Of A Complete Tree
2014/07/28
[Question] Construct a BST from Preorder Traversal
2014/07/28
[Question] Remove chars in Pairs
2014/07/28
[Question] Which loop is faster
2014/07/28
[Question] Find Min & Max in an Array Using Minimum Comparisons
2014/07/27
[Question] Breaking Chocolate Bars
2014/07/27
[Question] Check If Number Exists
2014/07/27
[Question] Matching Nuts And Bolts
2014/07/26
[Question] Elephant And Bananas
2014/07/26
[LeetCode Plus] Coins in a Line
2014/07/26
[Question] Fit 1*2 Dominos In 2*N Strip
2014/07/26
[Question] Reconstruct Tree From Pre-Order Traversal
2014/07/26
[LeetCode Plus] Sliding Window Maximum
2014/07/25
[Testing] Test Number Divisibility
2014/07/25
[Design] Multithreading Q&A
2014/07/25
[Question] Random Number Generate Question
2014/07/25
[Question] Truth tell brain teaser
2014/07/24
[Question] Find 10001st Prime (Sieve of E)
2014/07/24
[Fundamental] Quickselect
2014/07/24
[Design] Big Data - Top k Frequency
2014/07/24
[Design] Semaphore Mutex Toilet Example
2014/07/23
[Question] Find the first non-repeating character
2014/07/23
[Design] Multithreading Basics
2014/07/23
[Java OOP] Octal and Hexadecimal Numbers in Java
2014/07/23
[LeetCode Plus] Convert BST to Circular DLL
2014/07/22
[Question] Least Number after Deleting Digits
2014/07/22
[Question] Largest palindrome product
2014/07/22
[Question] Implement Stack using Two Queues
2014/07/21
[Question] Bucket Sort (bin sort)
2014/07/20
[Octopress] Clone Octopress Blog From A Different Computer
2014/07/20
[Question] Longest Substring with At Most Two Distinct Characters
2014/07/20
[Java OOP] OOP - 4 major principles
2014/07/20
[Question] Max Binary Gap
2014/07/20
[Question] Quick Sort
2014/07/12
[Design] Two's complement (2's complement)
2014/07/06
[NineChap 10] Additional Questions
2014/07/03
[Question] Check Power of 2
2014/07/03
[Question] Subarray with 0 Sum
2014/07/03
[Question] Subarray with Particular Sum
2014/07/03
[Question] Subarray with Sum Closest
2014/07/01
[LintCode] Trailing Zeros of Factorial
2014/06/30
[Question] Implement Queue using Stacks
2014/06/30
[Design] HashMap vs Hashtable vs HashSet
2014/06/30
[Question] Median in a stream of integers
2014/06/30
[Question] Implement a HashMap
2014/06/30
[Question] The Skyline Problem
2014/06/30
[Question] Min Stack
2014/06/29
[Question] Make a fair coin from a biased coin
2014/06/29
[Question] 0-1 Knapsack Problem
2014/06/29
[NineChap 9] Big Date, System Design and Resume (`)
2014/06/29
[Question] Coin Change Problem
2014/06/27
[LintCode] Majority Number II
2014/06/27
[LintCode] Majority Number
2014/06/27
[LintCode] Maximum Subarray II
2014/06/27
[LintCode] Majority Number III
2014/06/27
[NineChap 7] Data Structure
2014/06/27
[LintCode] Minimum Subarray
2014/06/27
[LintCode] Partition Array
2014/06/27
[Question] Single Number IV
2014/06/27
[NineChap 8] High Frequency Questions
2014/06/27
[Question] Single Number III
2014/06/26
[Question] Topology Sort
2014/06/26
[LintCode] Previous Permutation
2014/06/25
[NineChap 6] Graph and Search
2014/06/25
[Brain teaser] Khan Academy 8 brain teasers
2014/06/23
[LintCode] Longest Increasing Subsequence
2014/06/23
[LintCode] Longest Common Subsequence
2014/06/23
[NineChap 5.1] Dynamic Programming
2014/06/22
[Design] Cache and Page Replacement Algorithms
2014/06/17
[Question] Number Sum Sequence
2014/06/17
[NineChap 4.2] Linked List Additional
2014/06/17
[Brain teaser] 2 Eggs 100 Floors Puzzle
2014/06/16
[LeetCode Plus] Reverse linked list iteratively and recursively
2014/06/16
[Design] Time complexity calculation (Master theorem)
2014/06/16
[Question] Union and Intersection of two Linked Lists
2014/06/15
[LeetCode Plus] Binary Tree Serialize and Deserialize
2014/06/15
[NineChap 4.1] Linked List
2014/06/14
[Question] Binary Search Tree find upper/lower bound
2014/06/14
[NineChap 3.4] Binary Tree Additional
2014/06/14
[Java OOP] Java Global Variable
2014/06/13
[Question] Count negative in a 2D Sorted Matrix
2014/06/13
[Question] Iterator of Binary Search Tree
2014/06/13
[Java OOP] Java modifier and Access Level
2014/06/12
[Question] Search Range in BST (Trim a BST)
2014/06/11
[Question] Compare Mergesort and Quicksort
2014/06/11
[NineChap 1.2] Permutation
2014/06/10
[Design] BST Node Insertion / Deletion
2014/06/10
[NineChap 1.1] strStr and Coding Style
2014/06/09
[Question] First Character Appearing Only Once
2014/06/09
[LeetCode Plus] Lowest Common Ancestor of BST
2014/06/09
[LeetCode Plus] Lowest Common Ancestor of Binary Tree (II)
2014/06/09
[LeetCode Plus] Lowest Common Ancestor of Binary Tree (I)
2014/06/09
[NineChap 3.2] Binary Tree BFS
2014/06/09
[NineChap 3.1] Binary Tree DFS and Divide Conquer
2014/06/09
[LeetCode Plus] Searching a 2D Sorted Matrix
2014/06/09
[NineChap 3.3] Binary Search Tree
2014/06/08
[NineChap 2.2] Sorted Array
2014/06/07
[NineChap 2.1] Binary Search
2014/06/07
[LintCode] Recover Rotated Sorted Array
2014/06/04
[Testing] Software Testing
2014/06/03
[Question] ASCII, Utf-8, Utf-16 and Unicode
2014/06/03
[Question] Junit Hand-on Notes
2014/06/02
[LeetCode 145] Binary Tree Postorder Traversal
2014/06/02
[Design] Big Endian and Little Endian
2014/06/02
[LeetCode 150] Evaluate Reverse Polish Notation
2014/06/02
[LeetCode 143] Reorder List
2014/06/02
[LeetCode 146] LRU Cache
2014/06/02
[Design] Implemention of DFS using a Stack
2014/06/02
[LeetCode 149] Max Points on a Line
2014/06/02
[LeetCode 151] Reverse Words in a String
2014/06/01
[LeetCode 144] Binary Tree Preorder Traversal
2014/06/01
[LeetCode 142] Linked List Cycle II
2014/06/01
[LeetCode 141] Linked List Cycle
2014/06/01
[LeetCode 138] Copy List with Random Pointer
2014/06/01
[LeetCode 140] Word Break II
2014/06/01
[LeetCode 139] Word Break
2014/06/01
[LeetCode 148] Sort List
2014/05/31
[LeetCode 137] Single Number II
2014/05/31
[LeetCode 136] Single Number
2014/05/30
[LeetCode 134] Gas Station
2014/05/30
[LeetCode 135] Candy
2014/05/29
[LeetCode 132] Palindrome Partitioning II
2014/05/29
[LeetCode 133] Clone Graph
2014/05/29
[LeetCode 126] Word Ladder II (unsolvable)
2014/05/29
[LeetCode 147] Insertion Sort List
2014/05/28
[Design] DFS, BFS and space efficiency
2014/05/28
[LeetCode 128] Longest Consecutive Sequence
2014/05/28
[LeetCode 131] Palindrome Partitioning
2014/05/28
[LeetCode 129] Sum Root to Leaf Numbers
2014/05/28
[LeetCode 130] Surrounded Regions
2014/05/28
[LeetCode 127] Word Ladder
2014/05/27
[LeetCode 122] Best Time to Buy and Sell Stock II
2014/05/27
[LeetCode 123] Best Time to Buy and Sell Stock III
2014/05/27
[LeetCode 121] Best Time to Buy and Sell Stock
2014/05/27
[LeetCode 114] Flatten Binary Tree to Linked List
2014/05/27
[LeetCode 124] Binary Tree Maximum Path Sum
2014/05/27
[LeetCode 125] Valid Palindrome
2014/05/26
[LeetCode 106] Construct Binary Tree from Inorder and Postorder
2014/05/26
[LeetCode 105] Construct Binary Tree from Preorder and Inorder
2014/05/26
[LeetCode 119] Pascal's Triangle II
2014/05/26
[LeetCode 115] Distinct Subsequences
2014/05/26
[LeetCode 118] Pascal's Triangle
2014/05/26
[LeetCode 113] Path Sum II
2014/05/26
[LeetCode 112] Path Sum
2014/05/26
[LeetCode 116] Populating Next Right Pointers in Each Node
2014/05/26
[LeetCode 120] Triangle
2014/05/26
[LeetCode 117] Populating Next Right Pointers in Each Node II
2014/05/25
[LeetCode 110] Balanced Binary Tree
2014/05/25
[LeetCode 108] Convert Sorted Array to Binary Search Tree
2014/05/25
[LeetCode 109] Convert Sorted List to Binary Search Tree
2014/05/25
[LeetCode 101] Symmetric Tree
2014/05/25
[LeetCode 95] Unique Binary Search Trees II
2014/05/25
[LeetCode 98] Validate Binary Search Tree
2014/05/25
[LeetCode 96] Unique Binary Search Trees
2014/05/24
[LeetCode 107] Binary Tree Level Order Traversal II
2014/05/24
[LeetCode 102] Binary Tree Level Order Traversal
2014/05/24
[LeetCode 103] Binary Tree Zigzag Level Order Traversal
2014/05/24
[LeetCode 104] Maximum Depth of Binary Tree
2014/05/24
[LeetCode 111] Minimum Depth of Binary Tree
2014/05/24
[LeetCode 99] Recover Binary Search Tree
2014/05/24
[LeetCode 100] Same Tree
2014/05/23
[LeetCode 85] Maximal Rectangle
2014/05/23
[LeetCode 94] Binary Tree Inorder Traversal
2014/05/23
[LeetCode 93] Restore IP Addresses
2014/05/23
[LeetCode 97] Interleaving String
2014/05/22
[LeetCode 89] Gray Code
2014/05/22
[LeetCode 84] Largest Rectangle in Histogram
2014/05/22
[LeetCode 91] Decode Ways
2014/05/22
[LeetCode 88] Merge Sorted Array
2014/05/22
[LeetCode 86] Partition List
2014/05/22
[LeetCode 92] Reverse Linked List II
2014/05/22
[LeetCode 87] Scramble String
2014/05/21
[LeetCode 77] Combinations
2014/05/21
[LeetCode 80] Remove Duplicates from Sorted Array II
2014/05/21
[LeetCode 82] Remove Duplicates from Sorted List II
2014/05/21
[LeetCode 83] Remove Duplicates from Sorted List
2014/05/21
[LeetCode 90] Subsets II
2014/05/21
[LeetCode 78] Subsets
2014/05/21
[LeetCode 81] Search in Rotated Sorted Array II
2014/05/20
[LeetCode 67] Add Binary
2014/05/20
[LeetCode 70] Climbing Stairs
2014/05/20
[LeetCode 72] Edit Distance
2014/05/20
[LeetCode 76] Minimum Window Substring
2014/05/20
[LeetCode 66] Plus One
2014/05/20
[LeetCode 74] Search a 2D Matrix
2014/05/20
[LeetCode 73] Set Matrix Zeroes
2014/05/20
[LeetCode 71] Simplify Path
2014/05/20
[LeetCode 75] Sort Colors
2014/05/20
[LeetCode 69] Sqrt(x)
2014/05/20
[LeetCode 79] Word Search
2014/05/19
[LeetCode 53] Maximum Subarray
2014/05/19
[LeetCode 64] Minimum Path Sum
2014/05/19
[LeetCode 63] Unique Paths II
2014/05/19
[LeetCode 62] Unique Paths
2014/05/18
[LeetCode 60] Permutation Sequence
2014/05/18
[LeetCode 61] Rotate List
2014/05/17
[LeetCode 68] Text Justification (unsolvable)
2014/05/17
[LeetCode 57] Insert Interval
2014/05/17
[LeetCode 65] Valid Number (unsolvable)
2014/05/16
[LeetCode 56] Merge Intervals
2014/05/15
[LeetCode 55] Jump Game
2014/05/15
[LeetCode 58] Length of Last Word
2014/05/15
[LeetCode 52] N-Queens II
2014/05/15
[LeetCode 51] N-Queens
2014/05/15
[LeetCode 59] Spiral Matrix II
2014/05/15
[LeetCode 54] Spiral Matrix
2014/05/14
[LeetCode 50] Pow(x, n)
2014/05/14
[LeetCode 44] Wildcard Matching
2014/05/14
[LeetCode 49] Anagrams
2014/05/13
[LeetCode 41] First Missing Positive
2014/05/13
[LeetCode 46] Permutations
2014/05/13
[LeetCode 43] Multiply Strings
2014/05/13
[LeetCode 48] Rotate Image
2014/05/13
[LeetCode 45] Jump Game II
2014/05/13
[LeetCode 47] Permutations II
2014/05/13
[LeetCode 37] Sudoku Solver
2014/05/13
[LeetCode 42] Trapping Rain Water
2014/05/12
[LeetCode 40] Combination Sum II
2014/05/12
[LeetCode 39] Combination Sum
2014/05/12
[LeetCode 38] Count and Say
2014/05/11
[LeetCode 31] Next Permutation
2014/05/11
[LeetCode 35] Search Insert Position
2014/05/11
[LeetCode 32] Longest Valid Parentheses
2014/05/11
[LeetCode 33] Search in Rotated Sorted Array
2014/05/11
[LeetCode 34] Search for a Range
2014/05/11
[LeetCode 36] Valid Sudoku
2014/05/10
[LeetCode 25] Reverse Nodes in k-Groups
2014/05/10
[LeetCode 23] Merge k Sorted Lists
2014/05/10
[Fundamental] Heap (data structure)
2014/05/09
[LeetCode 29] Divide Two Integers
2014/05/09
[Fundamental] Java Bit Operation
2014/05/09
[LeetCode 28] Implement strStr
2014/05/09
[Fundamental] Recap on Java HashMap
2014/05/09
[LeetCode 30] Substring with Concatenation of All Words
2014/05/08
[LeetCode 22] Generate Parentheses
2014/05/08
[LeetCode 21] Merge Two Sorted Lists
2014/05/08
[LeetCode 26] Remove Duplicates from Sorted Array
2014/05/08
[LeetCode 27] Remove Element
2014/05/08
[LeetCode 24] Swap Nodes in Pairs
2014/05/08
[LeetCode 20] Valid Parentheses
2014/05/02
[LeetCode 18] 4Sum
2014/05/01
[LeetCode 16] 3Sum Closest
2014/05/01
[LeetCode 17] Letter Combinations of a Phone Number
2014/05/01
[LeetCode 15] 3Sum
2014/05/01
[LeetCode 19] Remove Nth Node From End of List
2014/04/30
[LeetCode 14] Longest Common Prefix
2014/04/29
[LeetCode 12] Integer to Roman
2014/04/29
[LeetCode 13] Roman to Integer
2014/04/28
[LeetCode 11] Container With Most Water
2014/04/28
[LeetCode 9] Palindrome Number
2014/04/28
[LeetCode 10] Regular Expression Matching
2014/04/28
[LeetCode 8] String to Integer (atoi)
2014/04/28
[LeetCode 6] ZigZag Conversion
2014/04/27
[LeetCode 5] Longest Palindromic Substring
2014/04/27
[LeetCode 7] Reverse Integer
2014/04/26
[LeetCode 2] Add Two Numbers
2014/04/26
[LeetCode 3] Longest Substring Without Repeating Characters
2014/04/25
[LeetCode 4] Median of Two Sorted Arrays
2014/04/25
[LeetCode 1] Two Sum
2014/04/24
LeetCode Statistics
2013/11/20
[Question] Get Max Number Game (minmax + dp)
2013/11/20
[Question] Insert Plus and Minus to Complete Expression
2013/11/19
[Amazon] Infix to Postfix conversion
2013/11/14
[Question] Count Arithmetic Slices
2013/11/14
[Question] Shuffle and Get Max Difference
2013/11/04
[Question] Number Of Bus Stations (meeting rooms)