Think in patterns.
Solve like it’s the interview.
hand-picked DSA problems in C#, Java, Python, C++ and JavaScript. Run your code, climb the leaderboard and keep your streak alive.
- 74problems
- 12core patterns
- 5languages
- 2 Lakh+learners trained
Bubble sort
ArraysO(n²)Running
Compare neighbours, swap when out of order.
Inorder traversal
TreesDFSO(n)
Visit order:
Breadth-first search
GraphsQueueO(V+E)
Level order:
Longest common subsequence
Dynamic ProgrammingO(mn)
dp[i][j] = best length for the first i and j characters.
Browse by pattern
Master the idea once, solve the whole family.
| # | Title | Acceptance | Difficulty |
|---|---|---|---|
| 51 | Binary Tree Preorder Traversal Tree · Recursion · Binary Tree | 79.85% | Easy |
| 52 | Permutation of A String String · Recursion | 66.00% | Medium |
| 53 | Smallest window of 0, 1 and 2 String | 50.00% | Easy |
| 54 | Roman Number to Integer String | 43.21% | Easy |
| 55 | Longest Palindromic Substring String | 34.80% | Medium |
| 56 | Form Anagram Groups String · Hashing | 69.80% | Medium |
| 57 | Longest Common Prefix Array · String | 44.20% | Easy |
| 58 | Length of the longest substring String | 50.00% | Medium |
| 59 | Smallest Window of All Characters String · Dynamic Programming | 50.00% | Hard |
| 60 | Bitonic Point Searching Algorithm | 58.67% | Easy |
| 61 | Alien Dictionary String | 47.81% | Hard |
| 62 | Find the String String | 72.98% | Hard |
| 63 | Reverse Words In A String String | 47.80% | Easy |
| 64 | First Occurrence In A String String | 50.08% | Medium |
| 65 | Longest Common Subsequence Array · String · Dynamic Programming | 50.00% | Medium |
| 66 | K-Pangrams String · Hashing | 20.91% | Medium |
| 67 | Winner of an election String · Hashing | 53.75% | Easy |
| 68 | Making A Large Island Graph · BFS · DFS | 52.36% | Hard |
| 69 | Stepping Numbers BFS · DFS | 48.44% | Medium |
| 70 | Course Schedule Graph · BFS · DFS | 51.77% | Medium |
| 71 | Redundant Parenthesis String · Stack | 51.49% | Hard |
| 72 | Find Kth Rotation Array · Stack · Searching Algorithm | 23.16% | Easy |
| 73 | Strings Rotations String | 43.83% | Medium |
| 74 | Unique Permutations String | 46.50% | Medium |
Practice that builds the habit
Three steps, repeated every day.
- 1
Pick a pattern
Start from an idea such as two pointers or BFS, then move through easy, medium and hard.
- 2
Code and run
Write in your language, run on sample cases and submit against every hidden test.
- 3
Climb the board
Every solve earns points. Keep a daily streak and see where you stand this month.
Want a plan, not just problems?
The DSA bootcamp adds structured lessons, live mentorship and mock interviews on top of this practice platform.
