Dashboard Questions Topics Companies Sheets

Stack

Topic

163 coding problems covering Stack concepts. Master this topic and improve your problem-solving skills.

163

Problems

Easy

Medium

Hard

Difficulty

All163 Easy23 Medium92 Hard48

Title	Solve	Difficulty	Companies	Topics
20. Valid Parentheses	Solve	Easy	Adobe+25	Stack String
32. Longest Valid Parentheses	Solve	Hard	Amazon+6	Dynamic Programming Stack+1
42. Trapping Rain Water	Solve	Hard	Adobe+21	Array Dynamic Programming+3
71. Simplify Path	Solve	Medium	Amazon+3	Stack String
84. Largest Rectangle in Histogram	Solve	Hard	Adobe+7	Array Monotonic Stack+1
85. Maximal Rectangle	Solve	Hard	Amazon+2	Array Dynamic Programming+3
94. Binary Tree Inorder Traversal	Solve	Easy	Adobe+13	Binary Tree Depth-First Search+2
114. Flatten Binary Tree to Linked List	Solve	Medium	Amazon+3	Binary Tree Depth-First Search+3
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
150. Evaluate Reverse Polish Notation	Solve	Medium	Amazon+6	Array Math+1
155. Min Stack	Solve	Medium	Adobe+7	Design Stack
173. Binary Search Tree Iterator	Solve	Medium	Amazon+5	Binary Search Tree Binary Tree+4
224. Basic Calculator	Solve	Hard	Adobe+8	Math Recursion+2
225. Implement Stack using Queues	Solve	Easy	Accenture+54	Design Queue+1
227. Basic Calculator II	Solve	Medium	Amazon+9	Math Stack+1
232. Implement Queue using Stacks	Solve	Easy	Amazon+4	Design Queue+1
234. Palindrome Linked List	Solve	Easy	Adobe+10	Linked List Recursion+2
255. Verify Preorder Sequence in Binary Search Tree	Solve	Medium	Oracle+2	Array Binary Search Tree+5
272. Closest Binary Search Tree Value II	Solve	Hard	Google+1	Binary Search Tree Binary Tree+5
316. Remove Duplicate Letters	Solve	Medium	Amazon+6	Greedy Monotonic Stack+2
321. Create Maximum Number	Solve	Hard	Apple+1	Array Greedy+3
331. Verify Preorder Serialization of a Binary Tree	Solve	Medium	Google	Binary Tree Stack+2
341. Flatten Nested List Iterator	Solve	Medium	Airbnb+10	Depth-First Search Design+4
364. Nested List Weight Sum II	Solve	Medium	LinkedIn	Breadth-First Search Depth-First Search+1
385. Mini Parser	Solve	Medium	Airbnb	Depth-First Search Stack+1
388. Longest Absolute File Path	Solve	Medium	Amazon+1	Depth-First Search Stack+1
394. Decode String	Solve	Medium	Adobe+16	Recursion Stack+1
402. Remove K Digits	Solve	Medium	Adobe+6	Greedy Monotonic Stack+2
426. Convert Binary Search Tree to Sorted Doubly Linked List	Solve	Medium	Amazon+2	Binary Search Tree Binary Tree+5
439. Ternary Expression Parser	Solve	Medium	Snapchat	Recursion Stack+1
445. Add Two Numbers II	Solve	Medium	Accenture+49	Linked List Math+1
456. 132 Pattern	Solve	Medium	Amazon+1	Array Binary Search+3
484. Find Permutation	Solve	Medium	Goldman Sachs+1	Array Greedy+2
488. Zuma Game	Solve	Hard	Baidu+2	Breadth-First Search Dynamic Programming+3
496. Next Greater Element I	Solve	Easy	Adobe+9	Array Hash Table+2
503. Next Greater Element II	Solve	Medium	Adobe+9	Array Monotonic Stack+1
536. Construct Binary Tree from String	Solve	Medium	Facebook	Binary Tree Depth-First Search+3
581. Shortest Unsorted Continuous Subarray	Solve	Medium	Amazon+1	Array Greedy+4
589. N-ary Tree Preorder Traversal	Solve	Easy	Google	Depth-First Search Stack+1
590. N-ary Tree Postorder Traversal	Solve	Easy	Amazon	Depth-First Search Stack+1
591. Tag Validator	Solve	Hard	Airbnb+1	Stack String
636. Exclusive Time of Functions	Solve	Medium	DoorDash+4	Array Stack
654. Maximum Binary Tree	Solve	Medium	Amazon	Array Binary Tree+4
678. Valid Parenthesis String	Solve	Medium	Amazon+4	Dynamic Programming Greedy+2
682. Baseball Game	Solve	Easy	Uber	Array Simulation+1
716. Max Stack	Solve	Hard	Amazon+6	Design Doubly-Linked List+3
726. Number of Atoms	Solve	Hard	Amazon+5	Hash Table Sorting+2
735. Asteroid Collision	Solve	Medium	Amazon+15	Array Simulation+1