All Questions
Tagged with stack interview-questions
19 questions
3
votes
2
answers
186
views
Check for max value in stack
Got this problem in a coding interview -
Get the max value of a stack in O(1).
The stack contains numbers only.
Please review my solution.
...
- 39
5
votes
1
answer
109
views
An alternative algorithm for sorting a stack using only one additional stack
From "Cracking the Coding Interview":
Write a program to sort a stack in ascending order (with biggest items on top). You may use at most one additional stack to hold items, but you may not copy ...
1
vote
2
answers
488
views
Leetcode - find if BST is valid or not
Given a binary tree, determine if it is a valid binary search tree
(BST).
Assume a BST is defined as follows:
The left subtree of a node contains only nodes with keys less than the
node'...
- 769
25
votes
3
answers
9k
views
Leetcode: Valid parentheses
Leetcode: Valid parentheses
Given a string containing just the characters (, ), {, ...
- 5,253
3
votes
0
answers
914
views
Find redundant braces in an input string
I am solving interview questions from here.
Problem : Write a program to validate if the input string has redundant braces
Return 0/1 :
...
- 1,769
6
votes
1
answer
1k
views
Multiple stacks implemented via a linked lists on top of single fixed-size array
Problem Statement
Originally, the problem is defined in the book as following:
Describe how you could use a single array to implement three stacks. — Cracking the Coding Interview (6th edition)
...
- 3,490
2
votes
1
answer
688
views
Stack using linked List
I have this problem with my interview. I was asked to implement a stack using a linked list.
Gist
...
- 131
4
votes
3
answers
159
views
Implementation of a simple stack with min method
The problem statement:
Implement a stack which has push and pop method and also min method whereas min method has \$O(1)\$ complexity.
From an interview standpoint, what mistakes would you point ...
- 219
5
votes
2
answers
220
views
Stack class in Ruby to calculate maximum number, get the average, pop, push
Is the class optimized enough to accept 1 million items in the stack?
...
- 53
8
votes
6
answers
1k
views
Implement queue using two stacks
Although it's a well-known algorithm, I thought to implement it from the perspective of a coding interview. I want to know if I can improve my code somehow. So, given the time constraint, is this a ...
- 5,127
8
votes
2
answers
2k
views
Implement 3 stacks using a single array in C++
One of the questions that is presented in Chapter 3 for Cracking the Coding Interview is this:
Describe how you could use a single array to implement 3 stacks
I'...
- 305
2
votes
4
answers
2k
views
Reverse Polish Notation Evaluation in Java
I would like to hear feedback about my code both in term of improving efficiency if possible or using other data structures. Also go ahead and let me know about code styles/patterns.
...
- 771
4
votes
1
answer
4k
views
Sort a stack in descending order
Maintain current element as the top element in the input stack. Pop all the elements on the ordered stack which are greater than the current element and push them in to the input stack and maintain a ...
- 363
11
votes
2
answers
2k
views
Stack having push, pop and return min in O(1)
I am using a class which is taking care of minimum value so far. Please let me know of any improvements or suggestions.
...
- 769
-3
votes
1
answer
212
views
Implemented Stack using array
I'm going to job interviews soon. How I can improve my coding style and write better code?
...
5
votes
4
answers
2k
views
Stack with a minimum
A practice interview question:
How would you design a stack which, in addition to push and pop, also has a function getMin which returns the minimum element? Push, pop and min should all operate in ...
- 153
4
votes
4
answers
2k
views
Class that implements a queue using two stacks
I am looking for a review of my code that implements a MyQueue class which implements a queue using two stacks.
...
user44869
16
votes
6
answers
35k
views
Implementing a Stack in Java for a technical interview
This code is based off the Stack implementation in Chapter 3 of Cracking The Coding Interview. I modified the code to make it compile and give me the correct output. I'd appreciate any feedback on ...
- 335
6
votes
2
answers
2k
views
Valid Parentheses
Given a string containing just the characters '(', ')', '{', '}', '['
and ']', determine if the input string is valid.
The brackets must close in the correct order, "()" and "()[]{}" are
all ...
- 1,025