| 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 |