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.
- 297problems
- 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 | Check Whether Three Numbers Form a Geometric Progression Data Structures Basics · Comparisons | 82.80% | Basic |
| 52 | Classify a Triangle Using Sides and Angles Data Structures Basics · Comparisons | 73.99% | Basic |
| 53 | Rotate Digits of a Number to the Right Data Structures Basics · String · Basics | 86.67% | Basic |
| 54 | Calculate Movie Ticket Price Based on Age, Day and Seat Type Data Structures Basics | 96.93% | Basic |
| 55 | Find the Second Largest of Four Numbers Data Structures Basics · Array · Searching Algorithms | 89.48% | Basic |
| 56 | Find the Middle Value Among Three Distinct Numbers Comparisons | 82.79% | Basic |
| 57 | Sort Three Numbers Using Conditional Statements Data Structures Basics · Sorting Algorithms · Sorting Algorithm | 93.23% | Basic |
| 58 | Check Whether Three Angles Form a Valid Triangle Data Structures Basics · Comparisons | 91.52% | Basic |
| 59 | Create a Menu-Driven Scientific Calculator Data Structures Basics | 100.00% | Basic |
| 60 | Game with String Heap | 53.96% | Medium |
| 61 | Kth largest element Heap | 64.92% | Medium |
| 62 | Min Number of Jumps Dynamic Programming | 50.48% | Medium |
| 63 | House Robber Dynamic Programming | 51.45% | Medium |
| 64 | Min Cost Climbing Stairs Dynamic Programming | 65.21% | Easy |
| 65 | Odd Even Graph Check Graph | 63.45% | Medium |
| 66 | Redundant Connection Graph | 68.71% | Medium |
| 67 | Detect Cycle in Undirected Graph (DFS) Graph | 67.77% | Medium |
| 68 | Path Existence Between Two Nodes Graph | 80.12% | Easy |
| 69 | Detect Cycle in Directed Graph (DFS) Graph | 67.67% | Medium |
| 70 | Level of Each Node Graph | 74.21% | Medium |
| 71 | BFS Traversal Graph | 83.12% | Easy |
| 72 | DFS Traversal Graph · DFS · Traversal | 85.64% | Easy |
| 73 | Flood Fill Recursion | 69.00% | Medium |
| 74 | Number of Islands Recursion | 66.00% | Medium |
| 75 | Remove Duplicates From A String String · Stack | 61.68% | Easy |
| 76 | Remove Consecutive Duplicates Recursion | 60.00% | Easy |
| 77 | Find Element in a Sorted Array Binary Search | 80.00% | Easy |
| 78 | Binary Tree Cameras Tree · Traversal · Binary Tree | 55.21% | Hard |
| 79 | Boundary Traversal Tree · Traversal · Binary Tree | 45.21% | Hard |
| 80 | Compare Leaf Traversal Tree · Traversal · Binary Tree | 77.95% | Medium |
| 81 | Binary Tree Post Order Traversal Tree · Recursion · Traversal | 79.59% | Easy |
| 82 | Inorder Successor in BST Tree · Traversal · Binary Tree | 60.12% | Medium |
| 83 | Kth Largest Element in BST Tree · Traversal · Binary Tree | 70.53% | Medium |
| 84 | Construct Tree from Inorder + Postorder Tree · Traversal · Binary Tree | 65.12% | Medium |
| 85 | Top View of Binary Tree Tree · Traversal · Binary Tree | 60.21% | Medium |
| 86 | Convert Sorted Array to BST Tree · Traversal · Binary Tree | 74.56% | Medium |
| 87 | Find Maximum in BST Tree · Traversal · Binary Tree | 85.54% | Easy |
| 88 | Find Minimum in BST Tree · Traversal · Binary Tree | 85.18% | Easy |
| 89 | Find Distance Between Two Nodes Tree · Traversal · Binary Tree | 62.45% | Medium |
| 90 | All Paths With Given Sum Tree · Traversal · Binary Tree | 74.23% | Medium |
| 91 | Maximum Root to Leaf Path Sum Tree · Traversal · Binary Tree | 72.15% | Medium |
| 92 | Count Non-Leaf Nodes In Binary Tree Tree · Traversal · Binary Tree | 60.48% | Easy |
| 93 | Minimum Depth of Binary Tree Tree · Traversal · Binary Tree | 60.25% | Medium |
| 94 | Construct Tree from Inorder + Preorder Tree · Traversal · Binary Tree | 70.00% | Medium |
| 95 | Right View of Binary Tree Tree · Traversal · Binary Tree | 74.36% | Medium |
| 96 | Lowest Common Ancestor in BST Tree · Traversal · Binary Tree | 70.50% | Medium |
| 97 | Kth Smallest Element in BST Tree · Traversal · Binary Tree | 76.77% | Medium |
| 98 | Maximum Path Sum in Binary Tree Tree · Traversal · Binary Tree | 58.59% | Hard |
| 99 | Delete Node In BST Tree · Traversal · Binary Tree | 65.20% | Medium |
| 100 | Validate BST Tree · Traversal · Binary Tree | 45.23% | 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?
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