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
101. Symmetric Tree	Solve	Easy	Adobe+7	Binary Tree Breadth-First Search+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
104. Maximum Depth of Binary Tree	Solve	Easy	Amazon+7	Binary Tree Breadth-First Search+2
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
108. Convert Sorted Array to Binary Search Tree	Solve	Easy	Amazon+4	Array Binary Search Tree+3
109. Convert Sorted List to Binary Search Tree	Solve	Medium	Amazon+3	Binary Search Tree Binary Tree+3
110. Balanced Binary Tree	Solve	Easy	Adobe+4	Binary Tree Depth-First Search+1
111. Minimum Depth of Binary Tree	Solve	Easy	Acko+15	Binary Tree Breadth-First Search+2
112. Path Sum	Solve	Easy	Amazon+4	Binary Tree Breadth-First Search+2
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
115. Distinct Subsequences	Solve	Hard	Amazon+2	Dynamic Programming String
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
118. Pascal's Triangle	Solve	Easy	Adobe+17	Array Dynamic Programming
119. Pascal's Triangle II	Solve	Easy	Adobe+3	Array Dynamic Programming
120. Triangle	Solve	Medium	Amazon+1	Array Dynamic Programming
121. Best Time to Buy and Sell Stock	Solve	Easy	Adobe+30	Array Dynamic Programming
122. Best Time to Buy and Sell Stock II	Solve	Medium	Amazon+7	Array Dynamic Programming+1
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
125. Valid Palindrome	Solve	Easy	Adobe+8	String Two Pointers
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
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
132. Palindrome Partitioning II	Solve	Hard	Amazon	Dynamic Programming String
133. Clone Graph	Solve	Medium	Amazon+5	Breadth-First Search Depth-First Search+2
134. Gas Station	Solve	Medium	Adobe+8	Array Greedy
135. Candy	Solve	Hard	Adobe+21	Array Greedy
136. Single Number	Solve	Easy	Adobe+8	Array Bit Manipulation
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
140. Word Break II	Solve	Hard	Adobe+7	Array Backtracking+5
141. Linked List Cycle	Solve	Easy	42gearMobilitySystems+131	Hash Table Linked List+1
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
144. Binary Tree Preorder Traversal	Solve	Easy	Adobe+2	Binary Tree Depth-First Search+2
145. Binary Tree Postorder Traversal	Solve	Easy	Facebook+1	Binary Tree Depth-First Search+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
149. Max Points on a Line	Solve	Hard	Amazon+4	Array Geometry+2
150. Evaluate Reverse Polish Notation	Solve	Medium	Amazon+6	Array Math+1