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
82. Remove Duplicates from Sorted List II	Solve	Medium	Amazon+2	Linked List Two Pointers
86. Partition List	Solve	Medium	Adobe+8	Linked List Two Pointers
89. Gray Code	Solve	Medium	Amazon	Backtracking Bit Manipulation+1
90. Subsets II	Solve	Medium	Adobe+3	Array Backtracking+1
91. Decode Ways	Solve	Medium	Amazon+8	Dynamic Programming String
92. Reverse Linked List II	Solve	Medium	1218 Global+122	Linked List
93. Restore IP Addresses	Solve	Medium	Amazon+6	Backtracking String
95. Unique Binary Search Trees II	Solve	Medium	Adobe+14	Backtracking Binary Search Tree+3
96. Unique Binary Search Trees	Solve	Medium	Amazon	Binary Search Tree Binary Tree+3
97. Interleaving String	Solve	Medium	Amazon+23	Dynamic Programming String
98. Validate Binary Search Tree	Solve	Medium	Adobe+8	Binary Search Tree Binary Tree+2
99. Recover Binary Search Tree	Solve	Medium	Adobe+5	Binary Search Tree Binary Tree+2
102. Binary Tree Level Order Traversal	Solve	Medium	Amazon+8	Binary Tree Breadth-First Search+1
103. Binary Tree Zigzag Level Order Traversal	Solve	Medium	Adobe+8	Binary Tree Breadth-First Search+1
105. Construct Binary Tree from Preorder and Inorder Traversal	Solve	Medium	Amazon+5	Array Binary Tree+3
106. Construct Binary Tree from Inorder and Postorder Traversal	Solve	Medium	Shopee	Array Binary Tree+3
107. Binary Tree Level Order Traversal II	Solve	Medium	Amazon	Binary Tree Breadth-First Search+1
109. Convert Sorted List to Binary Search Tree	Solve	Medium	Amazon+3	Binary Search Tree Binary Tree+3
113. Path Sum II	Solve	Medium	Amazon+4	Backtracking Binary Tree+2
114. Flatten Binary Tree to Linked List	Solve	Medium	Amazon+3	Binary Tree Depth-First Search+3
116. Populating Next Right Pointers in Each Node	Solve	Medium	Adobe+11	Binary Tree Breadth-First Search+3
117. Populating Next Right Pointers in Each Node II	Solve	Medium	Adobe+8	Binary Tree Breadth-First Search+3
120. Triangle	Solve	Medium	Amazon+1	Array Dynamic Programming
122. Best Time to Buy and Sell Stock II	Solve	Medium	Amazon+7	Array Dynamic Programming+1
128. Longest Consecutive Sequence	Solve	Medium	Adobe+9	Array Hash Table+1
129. Sum Root to Leaf Numbers	Solve	Medium	Amazon+4	Binary Tree Depth-First Search+1
130. Surrounded Regions	Solve	Medium	Bloomberg+3	Array Breadth-First Search+3
131. Palindrome Partitioning	Solve	Medium	Amazon+4	Backtracking Dynamic Programming+1
133. Clone Graph	Solve	Medium	Amazon+5	Breadth-First Search Depth-First Search+2
134. Gas Station	Solve	Medium	Adobe+8	Array Greedy
137. Single Number II	Solve	Medium	Amazon+10	Array Bit Manipulation
138. Copy List with Random Pointer	Solve	Medium	Aditya Birla group+30	Hash Table Linked List
139. Word Break	Solve	Medium	Accenture+38	Array Dynamic Programming+4
142. Linked List Cycle II	Solve	Medium	Amazon+1	Hash Table Linked List+1
143. Reorder List	Solve	Medium	Adobe+6	Linked List Recursion+2
146. LRU Cache	Solve	Medium	Accolite+56	Design Doubly-Linked List+2
147. Insertion Sort List	Solve	Medium	Google	Linked List Sorting
148. Sort List	Solve	Medium	Amazon+4	Divide and Conquer Linked List+3
150. Evaluate Reverse Polish Notation	Solve	Medium	Amazon+6	Array Math+1
151. Reverse Words in a String	Solve	Medium	Amazon+5	String Two Pointers
152. Maximum Product Subarray	Solve	Medium	Adobe+6	Array Dynamic Programming
153. Find Minimum in Rotated Sorted Array	Solve	Medium	Adobe+6	Array Binary Search
155. Min Stack	Solve	Medium	Adobe+7	Design Stack
156. Binary Tree Upside Down	Solve	Medium	LinkedIn	Binary Tree Depth-First Search+1
159. Longest Substring with At Most Two Distinct Characters	Solve	Medium	Amazon+1	Hash Table Sliding Window+1
161. One Edit Distance	Solve	Medium	Facebook+2	String Two Pointers
162. Find Peak Element	Solve	Medium	Amazon+8	Array Binary Search
164. Maximum Gap	Solve	Medium	Amazon+1	Array Bucket Sort+2
165. Compare Version Numbers	Solve	Medium	Amazon+3	String Two Pointers
166. Fraction to Recurring Decimal	Solve	Medium	Airbnb+3	Hash Table Math+1