25 DP Problems To Revise Before Interviews

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I've posted many complete resource guides recently - covering patterns, variations, and tons of problems for each topic. They're great for learning from scratch or extensive practice, but if your interview is already scheduled, covering 50-70 problems per topic just isn't realistic.
That's why I'm creating focused problem lists for each topic, just 10-25 essential problems that cover the complete breadth of what you need.
Starting today with DP: 25 carefully selected problems covering every major DP pattern for interviews. If you're interviewing at Google or other DSA-heavy companies, you might need extra practice, but for most tech interviews, this list is a solid foundation.

The 25 Essential Problems

1. Climbing Stairs - LeetCode 70

Pattern: Basic DP, Fibonacci recurrence
Why: Foundation of all DP, teaches recursion → memoization → tabulation

2. House Robber - LeetCode 198

Pattern: Include/Exclude decision
Why: Classic choice pattern, appears in many forms

3. House Robber II - LeetCode 213

Pattern: Circular array
Why: Teaches constraint handling

4. Decode Ways - LeetCode 91

Pattern: Count ways
Why: Common in interviews, multiple transitions

5. Jump Game II - LeetCode 45

Pattern: Minimum steps
Why: Optimization + greedy thinking

6. Unique Paths - LeetCode 62

Pattern: Basic 2D DP
Why: Foundation for all grid problems

7. Minimum Path Sum - LeetCode 64

Pattern: Cost optimization on grid
Why: Very common in interviews

8. Longest Common Subsequence - LeetCode 1143

Pattern: LCS (2D string DP)
Why: Foundation for all string comparison

9. Edit Distance - LeetCode 72

Pattern: String transformation
Why: Frequently asked, shows operations clearly

10. Partition Equal Subset Sum - LeetCode 416

Pattern: 0/1 Knapsack (subset sum)
Why: Foundation of knapsack, must know

11. Target Sum - LeetCode 494

Pattern: Count ways knapsack
Why: Shows knapsack in disguise

12. Coin Change - LeetCode 322

Pattern: Unbounded knapsack (minimize)
Why: Classic, very frequently asked

13. Coin Change II - LeetCode 518

Pattern: Unbounded knapsack (count ways)
Why: Complements Coin Change, different objective

14. Ones and Zeroes - LeetCode 474

Pattern: 2D knapsack
Why: Multiple constraints variation

15. Longest Increasing Subsequence - LeetCode 300

Pattern: LIS (know both O(n²) and O(n log n))
Why: Must-know, appears in many variations

16. Longest Palindromic Substring - LeetCode 5

Pattern: Palindrome problems
Why: Classic problem, multiple approaches

17. Palindromic Substrings - LeetCode 647

Pattern: Count palindromes
Why: Counting variant, builds on problem 16

18. Word Break - LeetCode 139

Pattern: String partition
Why: Common pattern, dictionary-based DP

19. Best Time to Buy and Sell Stock - LeetCode 121

Pattern: One transaction
Why: Foundation, simple but important

20. Best Time to Buy and Sell Stock II - LeetCode 122

Pattern: Unlimited transactions
Why: Introduces state concept

21. Best Time to Buy and Sell Stock with Cooldown - LeetCode 309

Pattern: State machine
Why: Teaches state transitions clearly

22. Best Time to Buy and Sell Stock IV - LeetCode 188

Pattern: K transactions (generalizes all stocks)
Why: Master this, master all stock problems

23. Unique Paths II - LeetCode 63

Pattern: Grid with obstacles
Why: Adds constraints to grid DP

24. Triangle - LeetCode 120

Pattern: Non-rectangular grid
Why: Variable width DP

25. Palindrome Partitioning II - LeetCode 132

Pattern: Partition DP
Why: Advanced string DP, commonly asked

Final Advice

Quality over quantity. 25 deeply understood problems > 100 half-understood problems.
Focus on patterns. When you solve problem 10 (Partition Equal Subset Sum), you're not learning one problem. You're learning the subset sum pattern that appears in dozens of problems.
Code, don't read. Reading solutions feels productive but doesn't work. You need to actually code these.
Time yourself. In interviews, you'll have 30-40 minutes. Practice under time pressure.
Revise. Solve each problem twice - once now, once 3 days later.

Check out my posts which may help you in your preparation :

These 25 problems are your DP foundation. Master them, and DP becomes one of your strengths instead of a weakness.

Now stop reading. Open problem 1. Start coding.

Good luck! 🚀

Comments (6)

The 25 Essential Problems

Final Advice

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