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 |
|---|---|---|---|
| 151 | Minimum Speed to Arrive on Time Binary Search | 69.00% | Medium |
| 152 | Koko Eating Bananas Binary Search | 68.00% | Medium |
| 153 | Peak Element In Rotated Array Recursion | 88.00% | Easy |
| 154 | Find Rotation Count Binary Search | 75.00% | Easy |
| 155 | Search in Rotated Array II Binary Search | 79.00% | Easy |
| 156 | Upper Bound Binary Search | 80.00% | Easy |
| 157 | Check if Element Exists Binary Search | 87.00% | Easy |
| 158 | Binary Search (Iterative) Binary Search | 79.00% | Easy |
| 159 | Generate All Subsequence Recursion | 56.00% | Medium |
| 160 | Check if Binary Tree is Balanced Recursion | 77.00% | Medium |
| 161 | Generate All Subsets Recursion | 60.00% | Medium |
| 162 | Count Nodes in Binary Tree Recursion | 64.00% | Medium |
| 163 | Letter Combinations of Phone Number Recursion | 60.00% | Medium |
| 164 | Tiling Problem Recursion | 50.00% | Medium |
| 165 | Permutation Without Duplicates Recursion | 67.00% | Medium |
| 166 | Combination Sum II Recursion | 76.00% | Medium |
| 167 | Target Sum Ways Recursion | 64.00% | Hard |
| 168 | Partition Equal Subset Recursion | 77.00% | Easy |
| 169 | Unique Path Recursion | 56.00% | Hard |
| 170 | Rat In A Maze Recursion | 38.00% | Hard |
| 171 | Permutation of an Array Array · Recursion | 68.00% | Medium |
| 172 | Permutation of A String String · Recursion | 66.00% | Medium |
| 173 | Subsets with Duplicates Recursion | 74.00% | Medium |
| 174 | Factorial of N Recursion | 60.00% | Easy |
| 175 | Count Ways To Reach Nth Stair Recursion | 60.00% | Medium |
| 176 | Friends Pairing Problem Recursion | 50.00% | Medium |
| 177 | Count Binary Strings Recursion | 60.00% | Medium |
| 178 | Fibonacci Series (Tree Recursion) Recursion | 60.00% | Medium |
| 179 | Check String Is Subsequence To Another Recursion | 75.00% | Medium |
| 180 | Convert String to Integer Recursion | 60.00% | Medium |
| 181 | Replace pi to 3.14 Recursion | 75.00% | Easy |
| 182 | Remove All Occurrence of A Character Recursion | 75.00% | Easy |
| 183 | Count Characters Recursion | 85.00% | Easy |
| 184 | Check Palindrome Recursion | 90.00% | Easy |
| 185 | Reverse A String Recursion | 48.00% | Easy |
| 186 | Product of All Array Elements Recursion | 80.00% | Easy |
| 187 | Sum of Array Elements Recursion | 58.00% | Easy |
| 188 | Reverse An Array Recursion | 85.00% | Easy |
| 189 | All Occurrence Of An Element Recursion | 59.00% | Easy |
| 190 | Last Occurrence Of An Element Recursion | 65.00% | Easy |
| 191 | First Occurrence Of An Element In An Array Recursion | 75.00% | Easy |
| 192 | Check Array is Sorted Recursion | 80.00% | Basic |
| 193 | Smallest window of 0, 1 and 2 String | 50.00% | Easy |
| 194 | Find Maximum / Minimum in Array Recursion | 75.00% | Easy |
| 195 | Print Array Elements Recursion | 50.00% | Easy |
| 196 | Fibonacci Series Recursion | 85.00% | Easy |
| 197 | Power of (a^b) Recursion | 85.00% | Easy |
| 198 | Roman Number to Integer String | 43.21% | Easy |
| 199 | Longest Palindromic Substring String | 34.80% | Medium |
| 200 | Missing And Repeating Array | 24.83% | Easy |
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.
