Dashboard Questions Topics Companies Sheets

Data Structures & Algorithms

Practice 3,374+ coding problems from top companies. Master DSA concepts and ace your interviews.

3,374

Problems

840

Easy

1762

Medium

772

Hard

Difficulty

All3374 Easy840 Medium1762 Hard772

Title	Solve	Difficulty	Companies	Topics
1. Two Sum	Solve	Easy	Accenture+29	Array Hash Table
2. Add Two Numbers	Solve	Medium	Adobe+14	Linked List Math+1
3. Longest Substring Without Repeating Characters	Solve	Medium	Adobe+20	Hash Table Sliding Window+1
4. Median of Two Sorted Arrays	Solve	Hard	Accolite+38	Array Binary Search+1
5. Longest Palindromic Substring	Solve	Medium	Accenture+50	Dynamic Programming String+1
6. Zigzag Conversion	Solve	Medium	Adobe+2	String
7. Reverse Integer	Solve	Medium	Adobe+10	Math
8. String to Integer (atoi)	Solve	Medium	Adobe+8	String
9. Palindrome Number	Solve	Easy	Accenture+8	Math
10. Regular Expression Matching	Solve	Hard	Adobe+8	Dynamic Programming Recursion+1
11. Container With Most Water	Solve	Medium	Adobe+8	Array Greedy+1
12. Integer to Roman	Solve	Medium	Adobe+8	Hash Table Math+1
13. Roman to Integer	Solve	Easy	Accenture+18	Hash Table Math+1
14. Longest Common Prefix	Solve	Easy	Adobe+9	String Trie
15. 3Sum	Solve	Medium	Adobe+21	Array Sorting+1
16. 3Sum Closest	Solve	Medium	Adobe+6	Array Sorting+1
17. Letter Combinations of a Phone Number	Solve	Medium	Airtel+34	Backtracking Hash Table+1
18. 4Sum	Solve	Medium	Adobe+8	Array Sorting+1
19. Remove Nth Node From End of List	Solve	Medium	Amazon+7	Linked List Two Pointers
20. Valid Parentheses	Solve	Easy	Adobe+25	Stack String
21. Merge Two Sorted Lists	Solve	Easy	Accenture+9	Linked List Recursion
22. Generate Parentheses	Solve	Medium	Adobe+12	Backtracking Dynamic Programming+1
23. Merge k Sorted Lists	Solve	Hard	Adobe+17	Divide and Conquer Heap (Priority Queue)+2
24. Swap Nodes in Pairs	Solve	Medium	Adobe+5	Linked List Recursion
25. Reverse Nodes in k-Group	Solve	Hard	Amazon+8	Linked List Recursion
26. Remove Duplicates from Sorted Array	Solve	Easy	Adobe+8	Array Two Pointers
27. Remove Element	Solve	Easy	Adobe+4	Array Two Pointers
28. Find the Index of the First Occurrence in a String	Solve	Easy	Amazon+4	String String Matching+1
29. Divide Two Integers	Solve	Medium	Adobe+6	Bit Manipulation Math
30. Substring with Concatenation of All Words	Solve	Hard	Amazon+4	Hash Table Sliding Window+1
31. Next Permutation	Solve	Medium	Adobe+19	Array Two Pointers
32. Longest Valid Parentheses	Solve	Hard	Amazon+6	Dynamic Programming Stack+1
33. Search in Rotated Sorted Array	Solve	Medium	Accenture+91	Array Binary Search
34. Find First and Last Position of Element in Sorted Array	Solve	Medium	Adobe+18	Array Binary Search
35. Search Insert Position	Solve	Easy	Adobe+8	Array Binary Search
36. Valid Sudoku	Solve	Medium	Amazon+9	Array Hash Table+1
37. Sudoku Solver	Solve	Hard	Adobe+11	Array Backtracking+2
38. Count and Say	Solve	Medium	Adobe+6	String
39. Combination Sum	Solve	Medium	Adobe+8	Array Backtracking
40. Combination Sum II	Solve	Medium	Amazon+4	Array Backtracking
41. First Missing Positive	Solve	Hard	Adobe+7	Array Hash Table
42. Trapping Rain Water	Solve	Hard	Adobe+21	Array Dynamic Programming+3
43. Multiply Strings	Solve	Medium	Adobe+5	Math Simulation+1
44. Wildcard Matching	Solve	Hard	Amazon+5	Dynamic Programming Greedy+2
45. Jump Game II	Solve	Medium	Adobe+9	Array Dynamic Programming+1
46. Permutations	Solve	Medium	Accenture+39	Array Backtracking
47. Permutations II	Solve	Medium	Amazon+1	Array Backtracking
48. Rotate Image	Solve	Medium	Adobe+9	Array Math+1
49. Group Anagrams	Solve	Medium	Adobe+23	Array Hash Table+2
50. Pow(x, n)	Solve	Medium	Adobe+29	Math Recursion