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
4. Median of Two Sorted Arrays	Solve	Hard	Accolite+38	Array Binary Search+1
10. Regular Expression Matching	Solve	Hard	Adobe+8	Dynamic Programming Recursion+1
23. Merge k Sorted Lists	Solve	Hard	Adobe+17	Divide and Conquer Heap (Priority Queue)+2
25. Reverse Nodes in k-Group	Solve	Hard	Amazon+8	Linked List Recursion
30. Substring with Concatenation of All Words	Solve	Hard	Amazon+4	Hash Table Sliding Window+1
32. Longest Valid Parentheses	Solve	Hard	Amazon+6	Dynamic Programming Stack+1
37. Sudoku Solver	Solve	Hard	Adobe+11	Array Backtracking+2
41. First Missing Positive	Solve	Hard	Adobe+7	Array Hash Table
42. Trapping Rain Water	Solve	Hard	Adobe+21	Array Dynamic Programming+3
44. Wildcard Matching	Solve	Hard	Amazon+5	Dynamic Programming Greedy+2
51. N-Queens	Solve	Hard	Adobe+7	Array Backtracking
52. N-Queens II	Solve	Hard	Bytedance+1	Backtracking
60. Permutation Sequence	Solve	Hard	Adobe+1	Math Recursion
65. Valid Number	Solve	Hard	Facebook+1	String
68. Text Justification	Solve	Hard	Adobe+25	Array Simulation+1
76. Minimum Window Substring	Solve	Hard	Adobe+9	Hash Table Sliding Window+1
84. Largest Rectangle in Histogram	Solve	Hard	Adobe+7	Array Monotonic Stack+1
85. Maximal Rectangle	Solve	Hard	Amazon+2	Array Dynamic Programming+3
87. Scramble String	Solve	Hard	Yahoo	Dynamic Programming String
115. Distinct Subsequences	Solve	Hard	Amazon+2	Dynamic Programming String
123. Best Time to Buy and Sell Stock III	Solve	Hard	Amazon+2	Array Dynamic Programming
124. Binary Tree Maximum Path Sum	Solve	Hard	Adobe+14	Binary Tree Depth-First Search+2
126. Word Ladder II	Solve	Hard	Amazon+4	Backtracking Breadth-First Search+2
127. Word Ladder	Solve	Hard	Adobe+8	Breadth-First Search Hash Table+1
132. Palindrome Partitioning II	Solve	Hard	Amazon	Dynamic Programming String
135. Candy	Solve	Hard	Adobe+21	Array Greedy
140. Word Break II	Solve	Hard	Adobe+7	Array Backtracking+5
149. Max Points on a Line	Solve	Hard	Amazon+4	Array Geometry+2
154. Find Minimum in Rotated Sorted Array II	Solve	Hard	Google	Array Binary Search
158. Read N Characters Given read4 II - Call Multiple Times	Solve	Hard	Facebook+3	Array Interactive+1
174. Dungeon Game	Solve	Hard	Amazon+1	Array Dynamic Programming+1
185. Department Top Three Salaries	Solve	Hard	Amazon+4	Database
188. Best Time to Buy and Sell Stock IV	Solve	Hard	Amazon+4	Array Dynamic Programming
212. Word Search II	Solve	Hard	Amazon+9	Array Backtracking+3
214. Shortest Palindrome	Solve	Hard	Apple+3	Hash Function Rolling Hash+2
218. The Skyline Problem	Solve	Hard	Cruise Automation+3	Array Binary Indexed Tree+5
220. Contains Duplicate III	Solve	Hard	Adobe+3	Array Bucket Sort+3
224. Basic Calculator	Solve	Hard	Adobe+8	Math Recursion+2
233. Number of Digit One	Solve	Hard	Google+1	Dynamic Programming Math+1
239. Sliding Window Maximum	Solve	Hard	Accion Labs India+66	Array Heap (Priority Queue)+3
248. Strobogrammatic Number III	Solve	Hard	Google	Array Recursion+1
262. Trips and Users	Solve	Hard	Adobe+3	Database
265. Paint House II	Solve	Hard	Facebook+2	Array Dynamic Programming
269. Alien Dictionary	Solve	Hard	Airbnb+8	Array Breadth-First Search+4
272. Closest Binary Search Tree Value II	Solve	Hard	Google+1	Binary Search Tree Binary Tree+5
273. Integer to English Words	Solve	Hard	Amazon+7	Math Recursion+1
282. Expression Add Operators	Solve	Hard	Facebook	Backtracking Math+1
295. Find Median from Data Stream	Solve	Hard	Adobe+33	Data Stream Design+3
296. Best Meeting Point	Solve	Hard	Expedia+2	Array Math+2
297. Serialize and Deserialize Binary Tree	Solve	Hard	Amazon+8	Binary Tree Breadth-First Search+4