This tag is for questions that came up in an interview.

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4
votes
1answer
56 views

Given a 2D array of digits, try to find the occurrence of a given 2D pattern of digits

My algorithm is quite simple. I simply iterate over the entire map arr and if I find the start of the combination I need to ...
2
votes
1answer
41 views

“Can a list of meetings all be scheduled in a conference room?”

I was given this question at an interview for a position I just got rejected by, so looking to improve and see what better answers there are! ...
6
votes
2answers
78 views

Linked list for interviews

I'm trying to learn linked lists so I can answer interview questions. Even though I've seen plenty of tutorials to understand how they supposedly work, I don't know if I am doing a good job because I ...
4
votes
0answers
64 views

Secret Santa Application : Practical Interview Test

I was given a practical task as part of an interview for a front-end developer position. There is a follow up interview and I'm looking for some constructive criticism / tough love to help me prepare. ...
3
votes
2answers
93 views

Check if sum can be found in array

Given an array a, check to see if z numbers inside a total up to ...
1
vote
2answers
68 views

Check if a linked list is a palindrome in O(n) time and O(1) space

I liked this problem because there are so many sub-problems that are interview problems in their own right-- (reverse linked list, find midpoint) ...
7
votes
1answer
56 views

Counting the overlapping intervals in the union of two sets

I had to recently implement a code to count the union of all intervals (if there are overlapping intervals) for an interview. I was provided with the following function stub: ...
6
votes
2answers
312 views

Reversing a domain name string in Java

Given a dot separated domain name, reverse the domain elements. Example: ...
9
votes
5answers
188 views

Reverse a domain name string

For an interview question, I was asked to do the following: Given a dot separated domain name, reverse the domain elements. Here are a few input/output examples: ...
5
votes
1answer
119 views

Weighted Probability Problem in Swift

I was asked a weighted probability question in a technical interview a few months ago that went something like this: Given an input of colors and an integer "weight" value, randomly return a color ...
8
votes
2answers
270 views

Printing an hourglass pattern

In a recent interview I have been asked to write a program to generate the following output: ...
8
votes
1answer
133 views

Analysing the results of various search engines and determining a winner

This is a programming challenge I submitted as part of a job interview, which I failed because it lacked "maintainability" and "patterns and best industry practices", so I guess we could all learn ...
6
votes
1answer
71 views

Text substitution templating function

In a recent interview I was asked to solve the below problem. Problem: Given a string with variables in them, e.g. ...
3
votes
1answer
93 views

Longest palindromic subsequence by memoization

I've written some code to solve the longest palindromic subsequence problem. ...
3
votes
1answer
136 views

Highest floor of a building from which to drop an egg without breaking it

Problem description: You have two eggs, and need to find the maximum floor of a 100-floor building from which you can drop the eggs without them breaking. Do this with as few attempts as possible. ...
8
votes
4answers
339 views

Implementing common fraction using TDD

Recently, during the interview, I was asked to implement basic arithmetic operations with common fractions using TDD. The task is fairly simple, but I was nervous so I did not do too well. :) Later on ...
10
votes
5answers
862 views

Maximum product of 3 integers in an int array

I want to find the maximum product that can be obtained from any 3 integers in an integer array. The optimal solution has time complexity of \$O(n)\$ and space complexity of \$O(1)\$. I managed to ...
6
votes
1answer
193 views

Finding anagrams

I recently had a potential employer send me a programming test to read through a file and write to another file all the words that were anagrams (two or more words containing the same letter). The ...
4
votes
2answers
93 views

Reverse all the words in a given string

I have read this and I want to know how the solution that I came up with in my interview compares with the top solution. ...
7
votes
4answers
240 views

Add one to a very large integer

I was asked to implement this in an interview a while back. I didn't pass the interview, mostly likely because it took me far too long to do. However, I'm interested to know how well implemented the ...
4
votes
2answers
112 views

App to list books from JSON data

I recently submitted the code for this for an 2 hour interview but I was rejected. The app shows book information with a image, title, and author. Each entry has a title but some entries have no ...
5
votes
2answers
130 views

Project Euler problem 79: deducing a passcode

For one place that I interviewed at (for a Python developer position) I worked with one of the devs on two Project Euler problems, one being problem 79. We talked through different approaches and came ...
2
votes
0answers
46 views

Are AVL trees equal? - revision 3

The original question Given two binary trees, return true if they are structurally identical, and false otherwise. Are AVL trees equal? Are AVL trees equal? - revision 2 This revision on ...
0
votes
1answer
40 views

Taking a node in rootA and finding a clone node in other tree

I was asked this as an interview question. I was also asked to assume that there is a function which can compare and say two nodes are identical. I would like to implement that function as well. I'm ...
2
votes
3answers
88 views

Reverse part of a linked list

I'm learning data structures. I'm working on linked lists at the moment, and I'd like to have a strong grasp on them. Below is the last problem I solved. I'd like to know what you think of the ...
5
votes
2answers
117 views

Bank account data structure

I need to model simple account data structure. The user should be able: to add a transaction get information about transaction take all transaction of some type sum a transaction and all its ...
6
votes
3answers
427 views

Checking balanced parenthesis string

I recently wrote a code in online recruitment test. It was very good. With each question, there were associated space and time limits check. If our code executed correctly within both limits, only ...
1
vote
1answer
51 views

Are AVL trees equal? - revision 2

Revision 1. This revision on GitHub In addition to the solution itself, I wrote tests for all the possible cases. It seems you have verified all execution paths are covered. You are ...
21
votes
3answers
2k views

Java Inventory System

I'm often applying to jobs just to test out my skills. I have recently applied to one, had to submit a Java problem, but got rejected. Could someone please review my application briefly and tell me ...
5
votes
2answers
274 views

Maze solver for 2D matrix in Ruby

I got rejected for a junior Ruby job entry where I had to solve a 2D matrix as a maze with walls. This is the main class: solver.rb ...
4
votes
1answer
78 views

Water accumulated between towers

I came across this interview question to find water accumulated between towers: You are given an input array whose each element represents the height of the tower. The width of every tower is 1. ...
6
votes
2answers
449 views

Implement Java hasNext() and next() in C++

Recently came upon this question asked in interview with major tech company. Implement Java's next and hasNext function in your favorite programming language. Here is the solution I came up ...
6
votes
1answer
236 views

JavaScript program to count lines of Java code

I've implemented a small program in JavaScript to count the number of lines of a string of java source code. This was done for one of the Code Kata exercise: ...
3
votes
4answers
113 views

Sending templatized e-mail to a million contacts

This code runs fine without a bug, I need to optimize this code for following interview requirement. Lets say i need to send it to 1 million contacts and emailBody is ~100Kb. What code optimization ...
2
votes
1answer
67 views

Get K most frequent tokens from a token stream

This is an interview problem: Given a token stream, find the K most frequent tokens in real time (the order of these k tokens does not matter). My approach: Use a hash table (...
4
votes
2answers
158 views

Function to compare phone numbers

I got rejected in tech screen yesterday. I was asked to write a JavaScript function and send it over email. I have also added hiring manager's response at the bottom. Could you please write a ...
6
votes
3answers
362 views

Finding the postion of a substring in a string

I am given two strings and return the position if in the larger string the smaller string is found. If not I am returning -1 for position. Any suggestions for improving my code. ...
7
votes
1answer
200 views

Are AVL trees equal?

I was inspired by this answer and decided to implement an AVL tree with the methods equals and hashCode as if I was asked to do ...
7
votes
1answer
128 views

Designing yet another coffee machine, Lombok style

After reading Designing a coffee machine, I decided to implement the same problem as an exercise to get to know Guava and Lombok. I used the problem statement from the given question: Design ...
-3
votes
1answer
103 views

Implemented Stack using array

I'm going to job interviews soon. How I can improve my coding style and write better code? ...
4
votes
1answer
95 views

Swap items of a linked list in pairs - revision 5

Here is the source of the question. Given a singly linked list, swap the list items in pairs (reconnect the pointers, not simply swap the values). For example: Before: A->B->C->D ...
2
votes
2answers
85 views

Hike in recession by a company based on criteria

I was going through design questions frequently being discussed in interviews and have found a problem which states: Consider a company which wants to process salary hikes of its employees ...
5
votes
4answers
672 views

Find the common element in two int arrays

I am preparing for a interview for a junior level c# position. I take two arrays and find the common int between both of them. Let me know if you have any feedback. ...
4
votes
3answers
789 views

Most common occurrence of an int in an array

I am prepping for a junior level interview in C#. I am hoping I can get some feedback on how to improve my code to print the most common occurrence of an int in an ...
1
vote
1answer
64 views

Swap items of a linked list in pairs - revision 4

Here is the source of the question. The solution on GitHub. Revision 1. Revision 2. Revision 3. @200_success' suggestions from revision 3: The iterator's ...
2
votes
1answer
37 views

Swap items of a linked list in pairs - revision 3

Here is the source of the question. Revision 1. Revision 2. When I started the second round of code review, I wanted to make sure that I had included all the possible input types. However, I ...
3
votes
1answer
83 views

Checking for uniqueness within a string

I saw this interview question in the book Cracking the Coding Interview: Implement an algorithm to determine if a string has all unique characters The authors solution uses bit-shifting for a ...
10
votes
4answers
964 views

Method to count all comments in single external C# file

I recently had an interview question: Write a method that counts all comments in a single external file. It was a timed question and I wanted to know if this is the best way to accomplish the ...
3
votes
1answer
89 views

Swap items of a linked list in pairs - revision 2

The first revision is available here and the code is available on GitHub. I modified the method reversePairs and added mSize to ...
11
votes
1answer
163 views

Concurrency interview

A little while back I had an interview where they posed a problem, in summary: Watch a certain directory, and process incoming JSON files These JSON files have various "Type" fields Every second ...