Striver's SDE sheet, from Raj Vikramaditya's takeUforward, is a widely shared interview problem list in India. It has changed several times, and the page most people link to now redirects to a different sheet. This page covers the classic sheet's current size and topics, what happened to the 191-problem version, how it differs from the A2Z sheet, which problems to repeat and a realistic schedule. For the longer learning sheet, see our Striver A2Z sheet guide.
How big the sheet is now
The classic SDE sheet page on takeUforward shows 156 problems, labelled Basic 10, Core 97 and Pro 48, in 27 short sections of 2 to 11 problems. 126 problems link to LeetCode and 125 have a video. Counts were read from each list's own site data in November 2026. Lists are edited from time to time, so numbers can drift.
- Many websites still describe the SDE sheet as 191 problems; that was an older version.
- The old SDE sheet address now redirects to Striver's 180, a pattern-based sheet with 179 problems in 17 modules (Basic 3, Core 107, Pro 69).
- So when someone says 'the Striver sheet', check which of the three they mean: the classic 156, Striver's 180 or the A2Z sheet.
The topics in order
The 27 sections keep the sheet's original order, which older copies label as days. Grouped by topic:
| Topic | Problems |
|---|---|
| Arrays (parts I to IV) | 20 |
| Linked list (parts I and II) | 11 |
| Linked list and arrays | 6 |
| Greedy | 6 |
| Recursion | 5 |
| Recursion and backtracking | 5 |
| Binary search | 6 |
| Heaps | 6 |
| Stack and queue (parts I and II) | 16 |
| Strings (parts I and II) | 12 |
| Binary tree (parts I to III) | 25 |
| Binary search tree (parts I and II) | 11 |
| Binary trees, miscellaneous | 4 |
| Graph (parts I and II) | 5 |
| Dynamic programming (parts I and II) | 12 |
| Trie | 6 |
The biggest blocks are binary trees, arrays and stacks and queues. Graphs are thin: the current page lists only Clone Graph, graph traversal, bipartite checking, Dijkstra's algorithm and Bellman-Ford.
SDE sheet vs A2Z vs Striver's 180
| Classic SDE sheet | Striver's 180 | A2Z sheet | |
|---|---|---|---|
| Size | 156 problems | 179 problems | 495 items (453 problems) |
| Organized by | Topic, in day-sized sections | Topic, then pattern inside each topic | A full course from basics |
| Graph coverage | 5 problems | 29 problems | 46 items |
| Best for | Revision before interviews | Pattern-based revision | Learning data structures from scratch |
For a comparison with an international list, see Striver SDE sheet vs NeetCode 150.
Problems worth repeating
A few problems carry techniques that interviewers return to often. Solve these twice, a week apart:
- Arrays: Next Permutation, Merge Overlapping Subintervals, Count Subarrays with Given XOR K and Reverse Pairs.
- Linked lists: Reverse in Groups of K, Clone a List with Random Pointers and Flattening a Linked List.
- Binary search: Median of Two Sorted Arrays, Allocate Minimum Number of Pages and Aggressive Cows, the 'search on the answer' trio.
- Stacks and queues: LRU Cache, LFU Cache, Largest Rectangle in a Histogram and Sliding Window Maximum.
- Trees: Morris traversal, Vertical Order Traversal, Maximum Path Sum and Serialize and Deserialize.
- Dynamic programming and tries: Matrix Chain Multiplication, Super Egg Drop and Maximum XOR of Two Numbers.
A realistic schedule
- Placement season, one section a day: 27 days plus a week of repeats, about five or six problems a day.
- Working professional: two sections a week on weekdays and repeats at weekends, about 12 to 14 weeks.
- Already practised: the Pro-labelled problems only, 48 of them, in two to three weeks.
Because graphs are thin, add graph practice from Striver's 180 or the NeetCode 150 roadmap. If you want a second Indian sheet with more problems per topic, the Love Babbar 450 sheet is the long option.
Turning a list into interview skill
Any list only helps if the practice transfers to problems you have not seen. These habits make the difference:
- Time-box every attempt: about 25 minutes for a medium before you read a solution.
- Keep a log with one line per problem: the pattern, the key idea and the complexity.
- Redo failed problems after three days, a week and three weeks, without looking at your old code.
- Explain your approach out loud before and while you code, as you would to an interviewer.
- In the last two weeks, switch to unseen problems without topic labels.
The patterns most lists are built on are explained in array and string patterns and tree, graph and recursion patterns.
Where CoPilot Interview fits
Finishing a list is not the same as passing an interview: interviewers score how you explain your approach, your trade-offs and your complexity out loud. CoPilot Interview is an AI interview assistant; its free AI mock interview asks coding questions, listens to your spoken explanation and scores it out of ten with a model answer, which is the part a problem list cannot train. The free plan gives 15 minutes a day of live help in sessions of up to 15 minutes, with AI mock interviews included. Online assessments and live coding rounds usually forbid outside help, so practice now and follow your employer's rules on the day.
Disclosure: CoPilot Interview is our product, so weigh what we say about it accordingly.
Frequently asked questions
How many problems are in Striver's SDE sheet?
The classic page shows 156 problems in 27 sections as of November 2026. The 191 figure comes from an older version.
What is Striver's 180?
A newer pattern-based sheet with 179 problems in 17 modules. The old SDE sheet address now redirects to it.
Should I do the SDE sheet or A2Z?
A2Z if you are learning data structures from the start; the SDE sheet or Striver's 180 if you are revising for interviews.
Is the SDE sheet enough for product companies?
It covers the core topics, but its graph section is small. Add graph problems from another list before interviews at companies with harder rounds.
Practice this interview before the real one
The AI mock interview builds questions from your resume and the job description, reads them aloud and scores each spoken answer out of 10. Included on the free plan.
Start a mock interview