Stack & Queue

No questions match those filters.

1. 01 Valid Parentheses Easy
2. 02 Encode and Decode Strings Medium
3. 03 Basic Calculator Hard
4. 04 Decode String Medium
5. 05 Simplify Path Medium
6. 06 Generate Parentheses Medium
7. 07 Daily Temperatures Medium
8. 08 Evaluate Reverse Polish Notation Medium
9. 09 Min Stack Medium
10. 10 Largest Rectangle in Histogram Hard
11. 11 Valid Parenthesis String Medium
12. 12 Implement Queue using Stacks Easy
13. 13 Asteroid Collision Medium
14. 14 Next Greater Element I Easy
15. 15 Basic Calculator II Medium
16. 16 Maximum Nesting Depth of Parentheses Easy
17. 17 Implement Stack Using Arrays Easy
18. 18 Implement Queue Using Arrays Easy
19. 19 Implement Min Stack Medium
20. 20 Next Greater Element Easy
21. 21 Next Smaller Element Medium
22. 22 Sum of Subarray Minimums Medium
23. 23 Find Next Greater Number with Same Digits Hard
24. 24 Balanced Parenthesis Check Easy
25. 25 Implement Stack Using Array Easy
26. 26 Implement Queue Using Array Easy
27. 27 Design a Stack with getMin() in O(1) Medium
28. 28 Find the Next Greater Element Easy
29. 29 The Celebrity Problem Medium
30. 30 Boolean Parenthesization Problem Hard
31. 31 Find the next greater number with the same set of digits Hard
32. 32 Balanced Parenthesis problem Easy
33. 33 Find maximum sum possible equal to the sum of three stacks Hard
34. 34 Remove Invalid Parentheses Hard
35. 35 Implement a stack from scratch Easy
36. 36 Implement a queue from scratch Easy
37. 37 Implement two stacks in an array Medium
38. 38 Find the middle element of a stack Medium
39. 39 Implement N stacks in an array Hard
40. 40 Check for balanced parentheses in an expression Easy
41. 41 Reverse a string using a stack Easy
42. 42 Design a stack that supports getMin() in O(1) time and O(1) extra space Medium
43. 43 Insert an element at the bottom of a stack without using any other data structure Medium
44. 44 Reverse a stack using recursion Medium
45. 45 Sort a stack using recursion Medium
46. 46 Implement a stack using a queue Medium
47. 47 Implement a stack using a deque Medium
48. 48 Stack permutations (check if an array is a stack permutation of another) Medium
49. 49 Implement a queue using a stack Medium
50. 50 Implement N queues in an array Hard
51. 51 Implement a circular queue Medium
52. 52 Reverse a queue using recursion Medium
53. 53 Reverse the first K elements of a queue Medium
54. 54 Interleave the first half of a queue with the second half Medium
55. 55 Queue-based approach for the first non-repeating character in a stream Medium
56. 56 Minimum Stack Medium