Questions

Easy

• 20. Valid Parentheses
• 155. Min Stack
• 225. Implement Stack using Queues
• 232. Implement Queue using Stacks
• 496. Next Greater Element I
• 844. Backspace String Compare
• 1047. Remove All Adjacent Duplicates In String

Medium

• 71. Simplify Path
• 150. Evaluate Reverse Polish Notation
• 227. Basic Calculator II
• 316. Remove Duplicate Letters
• 341. Flatten Nested List Iterator
• 385. Mini Parser
• 394. Decode String
• 402. Remove K Digits
• 456. 132 Pattern
• 503. Next Greater Element II