Topic | Section | Question | Solution | Difficulty |
---|---|---|---|---|
Arrays & Strings | 1.1 | Is Unique | Solution | Easy |
Arrays & Strings | 1.4 | Palindrome Permutation | Solution | Easy |
Arrays & Strings | 1.5 | One Away | Solution | Medium |
Arrays & Strings | 1.7 | Rotate Matrix | Solution | Hard |
Linked Lists | 2 - Intro | Implement a List | Solution | Easy |
Linked Lists | 2.1 | Remove Dups | Solution | Easy |
Linked Lists | 2.4 | Partition | Solution | Medium |
Linked Lists | 2.6 | Palindrome | Solution | Medium |
Linked Lists | 2.7 | Intersection | Solution | Medium |
Linked Lists | 2.8 | Loop Detection | Solution | Hard |
Stacks & Queues | 3 - Intro | Implement a Stack | Solution | Easy |
Stacks & Queues | 3 - Intro | Implement a Queue | Solution | Easy |
Stacks & Queues | 3.2 | Stack Min | Solution | Medium |
Stacks & Queues | 3.4 | Queue via Stacks | Solution | Medium |
Stacks & Queues | 3.5 | Sort Stack | Solution | Medium |
Trees & Graphs | 4 - Intro | Implement a TreeNode | Solution | Easy |
Trees & Graphs | 4 - Intro | Breadth-First Search (BFS) | Solution | Medium |
Trees & Graphs | 4 - Intro | Depth-First Search (DFS) | Solution | Medium |
Trees & Graphs | 4 - Intro | Implement a GraphNode | Solution | Easy |
Trees & Graphs | 4 - Intro | Pre-In-Post order Traversals | Solution | Easy |
Trees & Graphs | 4.01 | Route Between Nodes | Solution | Easy |
Trees & Graphs | 4.02 | Minimal Tree | Solution | Medium |
Trees & Graphs | 4.03 | List of Depths | Solution | Medium |
Trees & Graphs | 4.04 | Check Balanced | Solution | Medium |
Trees & Graphs | 4.05 | Validate BST | Solution | Medium |
Trees & Graphs | 4.06 | Successor | Solution | Medium |
Trees & Graphs | 4.07 | Build Order | Solution | Hard |
Trees & Graphs | 4.08 | First Common Ancestor | Solution | Hard |
Trees & Graphs | 4.11 | Random Node | Solution | Hard |
Trees & Graphs | 4.12 | Paths with Sum | Solution | Hard |
Object-Oriented Design | 7.12 | Hash Table | Solution | Hard |
Recursion & Dynamic Programming | 8 - Intro | Fibonacci | Solution | Easy |
Recursion & Dynamic Programming | 8.01 | Triple Step | Solution | Easy |
Recursion & Dynamic Programming | 8.03 | Magic Index | Solution | Medium |
Recursion & Dynamic Programming | 8.04 | Power Set | Solution | Hard |
Recursion & Dynamic Programming | 8.05 | Recursive Multiply | Solution | Medium |
Recursion & Dynamic Programming | 8.06 | Towers of Hanoi | Solution | Hard |
Recursion & Dynamic Programming | 8.08 | Permutations with Dups | Solution | Hard |
Recursion & Dynamic Programming | 8.09 | Parens | Solution | Medium |
Recursion & Dynamic Programming | 8.11 | Coins | Solution | Hard |
Recursion & Dynamic Programming | 8.12 | Eight Queens | Solution | Hard |
Recursion & Dynamic Programming | 8.13 | Stack of Boxes | Solution | Hard |
System Design & Scalability | 9 - Intro | 4 Ways to Divide Data | Solution | Medium |
System Design & Scalability | 9 - Intro | Find Words in Millions of Documents | Solution | Easy |
System Design & Scalability | 9.4 | Duplicate URLs | Solution | Medium |
System Design & Scalability | 9.5 | Cache | Solution | Medium |
Sorting & Searching | 10 - Intro | Binary Search | Solution | Easy |
Sorting & Searching | 10 - Intro | Merge Sort | Solution | Hard |
Sorting & Searching | 10 - Intro | Quick Sort | Solution | Hard |
Sorting & Searching | 10.02 | Group Anagrams | Solution | Medium |
Sorting & Searching | 10.03 | Search in Rotated Array | Solution | Medium |
Sorting & Searching | 10.04 | Sorted Search No Size | Solution | Medium |
Sorting & Searching | 10.06 | Sort Big File | Solution | Medium |
Sorting & Searching | 10.08 | Find Duplicates | Solution | Easy |
Sorting & Searching | 10.09 | Sorted Matrix Search | Solution | Medium |
Sorting & Searching | 10.10 | Rank from Stream | Solution | Hard |
Sorting & Searching | 10.11 | Peaks and Valleys | Solution | Easy |
More Questions | Book Intro | Math cubes | Solution | Medium |
More Questions | 7.09 | Circular Array | Solution | Medium |
More Questions | 13.5 | TreeMap, HashMap, LinkedHashMap | Solution | Easy |
More Questions | 16.04 | Tic Tac Win | Solution | Medium |
More Questions | 16.05 | Factorial Zeros | Solution | Medium |
More Questions | 16.06 | Smallest Difference | Solution | Medium |
More Questions | 16.08 | English Int | Solution | Medium |
More Questions | 16.10 | Living People | Solution | Medium |
More Questions | 16.11 | Diving Board | Solution | Easy |
More Questions | 16.14 | Best Line | Solution | Hard |
More Questions | 16.16 | Sub Sort | Solution | Medium |
More Questions | 16.17 | Contiguous Sequence | Solution | Medium |
More Questions | 16.18 | Pattern Matching | Solution | Hard |
More Questions | 16.19 | Pond Sizes | Solution | Medium |
More Questions | 16.20 | T9 | Solution | Medium |
More Questions | 16.21 | Sum Swap | Solution | Medium |
More Questions | 16.22 | Langtons Ant | Solution | Easy |
More Questions | 16.23 | Rand7 from Rand5 | Solution | Medium |
More Questions | 16.24 | Pairs with Sum | Solution | Medium |
More Questions | 16.25 | LRU Cache | Solution | Hard |
More Questions | 17.01 | Add Without Plus | Solution | Medium |
More Questions | 17.02 | Shuffle | Solution | Hard |
More Questions | 17.03 | Random Set | Solution | Hard |
More Questions | 17.05 | Letters and Numbers | Solution | Hard |
More Questions | 17.07 | Baby Names | Solution | Easy |
More Questions | 17.09 | Kth Multiple | Solution | Hard |
More Questions | 17.10 | Majority Element | Solution | Hard |
More Questions | 17.11 | Word Distance | Solution | Medium |
More Questions | 17.12 | BiNode | Solution | Hard |
More Questions | 17.14 | Smallest K | Solution | Medium |
More Questions | 17.15 | Longest Word | Solution | Hard |
More Questions | 17.16 | The Masseuse | Solution | Medium |
More Questions | 17.18 | Shortest Supersequence | Solution | Hard |
More Questions | 17.19 | Missing Two | Solution | Medium |
More Questions | 17.20 | Continous Median | Solution | Hard |
More Questions | 17.21 | Volume of Histogram | Solution | Medium |
More Questions | 17.22 | Word Transformer | Solution | Hard |
More Questions | 17.23 | Max Black Square | Solution | Hard |
More Questions | 17.24 | Max Submatrix | Solution | Hard |
From LeetCode
# | Question | Solution | Difficulty |
---|---|---|---|
15 | 3sum | Solution | Medium |
16 | 3sum Closest | Solution | Medium |
20 | Valid Parentheses | Solution | Easy |
21 | Merge Two Sorted Lists | Solution | Easy |
23 | Merge k Sorted Lists | Solution | Hard |
98 | Validate Binary Search Tree | Solution | Medium |
104 | Maximum Depth of Binary Tree | Solution | Easy |
136 | Single Number | Solution | Easy |
141 | Linked List Cycle | Solution | Easy |
143 | Reorder List | Solution | Medium |
151 | Reverse Words in a String | Solution | Medium |
189 | Rotate Array | Solution | Easy |
200 | Number of Islands | Solution | Medium |
206 | Reverse Linked List | Solution | Easy |
560 | Subarray Sum Equals K | Solution | Medium |
695 | Max Area of Island | Solution | Medium |
1013 | Pairs of Songs With Total Durations Divisible by 60 | Solution | Easy |
From HackerRank
Question | Solution | Difficulty |
---|---|---|
Linked List - Print in Reverse | Solution | Easy |
Linked List - Get Node Value | Solution | Easy |
Counting Sort | Solution | Medium |
Reverse a Doubly Linked List | Solution | Medium |
Tree - Level Order Traversal | Solution | Medium |
Java 1D Array | Solution | Medium |
Java Dequeue | Solution | Medium |
Java Singleton | Solution | Medium |
Contacts | Solution | Hard |
Coin Change | Solution | Hard |
Array Manipulation | Solution | Hard |
Topic | Section | Question | Solution | Difficulty |
---|---|---|---|---|
Arrays & Strings | 1.2 | Check Permutations | Solution | Easy |
Arrays & Strings | 1.3 | URLify | Solution | Easy |
Arrays & Strings | 1.8 | Zero Matrix | Solution | Easy |
Arrays & Strings | 1.9 | String Rotation | Solution | Easy |
Linked Lists | 2.2 | Return Kth to Last | Solution | Easy |
Linked Lists | 2.3 | Delete Middle Node | Solution | Easy |
Linked Lists | 2.5 | Sum Lists | Solution | Medium |
Stacks & Queues | 3.1 | Three in One | Solution | Medium |
Trees & Graphs | 4.09 | BST Sequences | Solution | Hard |
Trees & Graphs | 4.10 | Check Subtree | Solution | Medium |
Bit Manipulation | 5 - Intro | BitFunctions: getBit | Solution | Easy |
Bit Manipulation | 5 - Intro | BitFunctions: setBit | Solution | Easy |
Bit Manipulation | 5 - Intro | BitFunctions: clearBit | Solution | Easy |
Bit Manipulation | 5.2 | Binary to String | Solution | Medium |
Bit Manipulation | 5.3 | Flip Bit to Win | Solution | Medium |
Bit Manipulation | 5.4 | Next Number | Solution | Hard |
Bit Manipulation | 5.6 | Conversion | Solution | Easy |
Bit Manipulation | 5.7 | Pairwise Swap | Solution | Medium |
Math & Logic Puzzles | 6 - Intro | Prime - isPrime | Solution | Easy |
Math & Logic Puzzles | 6 - Intro | Prime - generate Primes | Solution | Medium |
Recursion & Dynamic Programming | 8.02 | Robot in a Grid | Solution | Hard |
Sorted Merge | 10.01 | Sorted Merge | Solution | Easy |
Sorting & Searching | 10.07 | Missing Int | Solution | Hard |
Threads & Locks | 15.1 | Thread vs. Process | Solution | Medium |
Threads & Locks | 15.4 | Deadlock-Free Class | Solution | Medium |
Threads & Locks | 15.5 | Call in Order | Solution | Medium |
Threads & Locks | 15.6 | Synchronized Methods | Solution | Easy |
More Questions | 16.01 | Number Swapper | Solution | Medium |
More Questions | 16.15 | Master Mind | Solution | Medium |
From HackerRank
Question | Solution | Difficulty |
---|---|---|
Electronics Shop | Solution | Easy |
Minimum Distances | Solution | Easy |
Find Digits | Solution | Easy |
Picking Numbers | Solution | Easy |
Ransom Note | Solution | Easy |
Sansa and XOR | Solution | Easy |
Making Anagrams | Solution | Medium |
Repeated String | Solution | Medium |
Inserting a Node Into a Sorted Doubly Linked List | Solution | Medium |
Super Reduced String | Solution | Medium |
Caesar Cipher | Solution | Medium |
Gemstones | Solution | Medium |
Maximizing XOR | Solution | Medium |
Sum vs XOR | Solution | Hard |