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Stacks & Queues

38 questions in this topic
Questions for Stacks & Queues topic - 38 total questions
# Status Problem Difficulty Marks Save Notes Revision
1
Implement Stack from Scratch
Easy 0
2
Implement Queue from Scratch
Easy 0
3
Implement 2 stack in an array
Medium 0
4
find the middle element of a stack
Medium 0
5
Implement "N" stacks in an Array
Medium 0
6
Check the expression has valid or Balanced parenthesis or not.
Easy 0
7
Reverse a String using Stack
Easy 0
8
Design a Stack that supports getMin() in O(1) time and O(1) extra space.
Medium 0
9
Find the next Greater element
Easy 0
10
The celebrity Problem
Medium 0
11
Arithmetic Expression evaluation
Medium 0
12
Evaluation of Postfix expression
Medium 0
13
Implement a method to insert an element at its bottom without using any other data structure.
Medium 0
14
Reverse a stack using recursion
Easy 0
15
Sort a Stack using recursion
Medium 0
16
Merge Overlapping Intervals
Medium 0
17
Largest rectangular Area in Histogram
Medium 0
18
Length of the Longest Valid Substring
Medium 0
19
Expression contains redundant bracket or not
Medium 0
20
Implement Stack using Queue
Easy 0
21
Implement Stack using Deque
Easy 0
22
Stack Permutations (Check if an array is stack permutation of other)
Medium 0
23
Implement Queue using Stack
Easy 0
24
Implement "n" queue in an array
Medium 0
25
Implement a Circular queue
Medium 0
26
LRU Cache Implementationa
Medium 0
27
Reverse a Queue using recursion
Easy 0
28
Reverse the first “K” elements of a queue
Easy 0
29
Interleave the first half of the queue with second half
Medium 0
30
Find the first circular tour that visits all Petrol Pumps
Medium 0
31
Minimum time required to rot all oranges
Medium 0
32
Distance of nearest cell having 1 in a binary matrix
Medium 0
33
First negative integer in every window of size “k”
Medium 0
34
Check if all levels of two trees are anagrams or not.
Medium 0
35
Sum of minimum and maximum elements of all subarrays of size “k”.
Medium 0
36
Minimum sum of squares of character counts in a given string after removing “k” characters.
Medium 0
37
Queue based approach or first non-repeating character in a stream.
Medium 0
38
Next Smaller Element
Medium 0