28
votes
11answers
3k views

Searching in an array in less than O(n) time

I have an array where each element is either one less or one greater than the preceding element \$\{x_i = x_{i-1} \pm 1\}\$. I wish to find an element in it in less than \$O(n)\$ time. I've ...
24
votes
2answers
2k views

Interview screw-up after piece of asynchronous callback code

I was screwed up after submitting this piece of work. But I have no feedback to know what "BAD" things are inside this block of code. The requirements are like this: Connect to the server on a ...
16
votes
10answers
2k views

Find all the missing number(s)

Recently I've attended an interview, where I faced the below question: Question: "There is an sorted array. You need to find all the missing numbers. Write the complete code, without using any ...
15
votes
4answers
2k views

Reverse a string word by word

Given an input string, reverse the string word by word. For example: Given s = "the sky is blue", return ...
14
votes
6answers
1k views

Array whose values are the product of every other integer

I was asked the following interview question over the phone: Given an array of integers, produce an array whose values are the product of every other integer excluding the current index. ...
14
votes
7answers
20k views

Finding repeating numbers in an array

I want to search through an array of n numbers and find the numbers that are repeated. So far I have this code, which does the job, but I find it to be a rather cumbersome method, but I can't seem to ...
14
votes
4answers
734 views

Modelling a Call Center

This is the requirement I have (from the book: Cracking the Coding Interview) Imagine you have a call center with three levels of employees: fresher, technical lead (TL), and product manager (PM). ...
13
votes
5answers
1k views

Longest palindrome in a string

Please be brutal, and judge my code as if it was written at a top 3 tech company, straight out of college. (The method signature, and input parameter is given by the problem, so don't worry about ...
13
votes
4answers
632 views

Determining if an answer can be generated

How can I improve my code below for the following question? While it works, I am not satisfied with how it looks; I was hoping I can somehow keep it recursive, and have the ans filled up inside the ...
13
votes
4answers
512 views

Finding the sub-array with the maximum sum - my approach

This is the code I ended up with that implements the approach I described in a recent answer to another question about the same problem The basic idea here is to not loop through more things than ...
12
votes
6answers
2k views

Implementing a Stack in Java for 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 ...
12
votes
3answers
313 views

Reversing k-sized sequences in a linked-list

Here is my solution to this problem; please be brutally honest/strict, if I would have written this code, in a 45 minute interview, what would you think? (I am aiming for Google,Facebook). Here is ...
11
votes
5answers
507 views

Set matrix zeros

I solved this problem in about 11 minutes (with all 50+ test cases passed). I think most of you already know me by now, and I truly appreciate your advice, but please be brutal and judge me as if I ...
10
votes
3answers
465 views

Exception handling, et al - How do I make this web downloader not “poor”?

I haven't done Java coding in years, but I thought I would give it a shot for a job interview. I have a few questions: Why is this error handling considered poor? How am I supposed to be doing it? ...
8
votes
3answers
556 views

Longest Common Prefix in an array of Strings

Please be brutal, and treat this as if I was at an interview at a top 5 tech firm. Question: Write a function to find the longest common prefix string amongst an array of strings. Time it ...
8
votes
2answers
88 views

Sorting and searching problem related to a group of people standing in a rectangle

Please be brutal, and let me know how I've done on this problem, provided I coded it at an interview for a top tech firm. Time it took me: 44 minutes Worst case time complexity: O(n2)? Am I right? ...
8
votes
4answers
700 views

Given two sorted arrays, add the elements of the second array into the first

In Cracking the Coding Interview by Gayle Laakmann McDowell, there's a question that asks you to write code for the following: Given two sorted arrays, A and B. Write a method merging the elements ...
7
votes
11answers
15k views

Optimizing Java Anagram checker (compare 2 strings)

An anagram is like a mix-up of the letters in a string: pots is an anagram of stop Wilma is an anagram of ilWma I am going through the book Cracking the Coding Interview and in the ...
7
votes
5answers
3k views

Find missing number from list

I was asked a question in an interview the other day: You have an array list of numbers from 1 to 100, the problem is that one number is missing. How would you find that number? This is a mock ...
7
votes
4answers
498 views

Find the subarray with the max sum

In an interview I was asked to solve the following problem: find a subarray with max sum I have written a piece of code for the same. I need your help in reviewing this code. ...
7
votes
3answers
490 views

Find Minimum Number of coins

Please be brutal, and treat this as a top 5 technical interview. I am trying to follow Google's way of writing Java code, as per their .pdf file online of code review. (Side note: do any of you see ...
7
votes
4answers
322 views

First missing positive

As usual, please be brutally honest with your opinion of my code, and how you would judge it if I were to code this at a top-tier tech company for an interview(think Google, MSFT, Facebook, etc). My ...
7
votes
4answers
3k views

Checking if three numbers sum to a given number

I'm working on the following interview practice problem, and got the following solution, which runs in worst case n! time (best case constant), and I'm trying to ...
7
votes
3answers
301 views

Simplifying a path

Please be super brutal, and treat this as a top technical interview. Worst case analysis: \$O(n)\$ (please confirm) Space complexity: \$O(n)\$ Problem: Given an absolute path for a file ...
7
votes
3answers
269 views

Number to words in left to right direction

I have faced one logical question in an interview: If we enter a number it will convert into individual strings and display in same order. Ex: If I enter 564 ...
7
votes
4answers
469 views

Calculate final test score from a list of test results

Recently I have given an interview to a widely well-known technology firm. The first interview was general and it went well but they rejected based on some technical things. They did not mention it so ...
7
votes
2answers
181 views

Missing level of technical depth (Common Ancestor)

I recently have given a coding test in a reputable IT company. There were three coding questions. They refused me by saying that as we felt they didn't demonstrate the level of technical depth ...
7
votes
1answer
63 views

Finding the length of shortest transformation sequence from start to end

Please treat this as a interview at a top tech firm, and share your thoughts on how you think I did. Be honest, and leave no stone unturned. Problem: Given two words (start and end), and a ...
6
votes
2answers
276 views

Spring password validator library

I recently got rejected at a job interview for submitting this: https://bitbucket.org/gnerr/password-validator The interviewer asked for a password validation library that was configurable via ...
6
votes
2answers
451 views

Simple calculator for an interview

Question: Simple Calculator Input loaded from file. Instructions can be any binary operators. Ignore math precedence. Last input is apply and a number e.g. "apply 5". Calc is then ...
6
votes
4answers
2k views

Linked list loop detection in Java(interview question)

A schoolmate is going through the interview process, and was posed the question of detecting if a linked list data structure has an infinite loop in it. I wrote this example, and wanted to see what ...
6
votes
2answers
414 views

Generating a list of alternatively positioned odd and even number out of an array of unsorted integers

I had an half an hour interview with Microsoft for an intern position. I was asked to generate a list of alternatively positioned odd and even number out of an array of unsorted integers. I guess it ...
6
votes
2answers
105 views

Breaking of a sentence

(Method signature is given with parameters) Try to visualize me writing this code at an interview, and please be brutal while judging it. Problem: Given a string s and a dictionary of words ...
6
votes
2answers
235 views

Simple application for finding local restaurants

I was asked to create a test APK file by a company HR when I applied for an Android developers job, Specification: The goal is to develop a simple application which finds the local restaurants. ...
6
votes
2answers
302 views

Add one to a number represented as an array of digits

I submitted this problem for an interview, and I was wondering if I could have done better. My solution works, and I solved in about 12-15 minutes. I feel like I did a bad job with the code. Please ...
6
votes
3answers
129 views

How to extract elements from multiple sorted list efficiently?

Problem Statement:- I was ask this interview question recently.. I was able to come up with the below code only which runs in O(k log n)- Given k <= n sorted arrays each of size n, there exists ...
6
votes
3answers
2k views

Approximate String Matching Interview Question

I was working on the challenge Save Humanity from Interviewstreet for a while then gave up, solved a few other challenges, and have come back to it again. The code below generates the correct ...
6
votes
1answer
55 views

Finding the sub-array with maximum sum - my slow approach

I decided to give the maximum sub-array sum problem an interesting go, however I will assure you that it doesn't perform well, and that I would never put this in production. I'd like a review on ...
5
votes
3answers
1k views

Client Sends XML, Server Parses XML, Queues Up and Executes Commands

I recently had a Java interview where I was asked to write a client-server application. I don't code primarily in Java, but with my preliminary Java knowledge, I thought I built a reasonable working ...
5
votes
3answers
1k views

Find elements occurring even number of times in an integer array

I came across an interview question, which is like this: You have an array of integers, such that each integer is present an odd number of time, except 3 of them. Find the three numbers. I tried ...
5
votes
3answers
319 views

Implementing a queue in Java for a technical interview

This code is based off the Queue implementation in Chapter 3 of Cracking The Coding Interview. I modified the code to make it compile and give me the correct ...
5
votes
3answers
399 views

interview question, friends, movies and likes

I was recently asked to implement an interface for a job interview. the class has methods to add customers and movies, the customers can watch or like movies and add friends. there are methods to get ...
5
votes
4answers
248 views

Find the sum along root-to-leaf paths of a tree

Most of you already know me, please be brutal, and treat this code as if it was written at a top tech interview company. Question: Given a binary tree and a sum, find all root-to-leaf paths where ...
5
votes
2answers
1k views

Ways to improve my coding test FizzBuzz solution for a TDD role?

I had an interview recently where I was asked to produce the traditional FizzBuzz solution: Output a list of numbers from 1 to 100. For all multiples of 3 and 5, the number is replaced ...
5
votes
1answer
180 views

Missing level of technical depth (Recursive to Iterative)

I recently have given a coding test in a reputable IT company. There were three coding questions. They refused me by saying that as we felt they didn't demonstrate the level of technical depth ...
5
votes
2answers
138 views

Missing level of technical depth (Flatten Tree)

I recently have given a coding test in a reputable IT company. There were three coding questions. They refused me by saying that as we felt they didn't demonstrate the level of technical depth ...
5
votes
2answers
128 views

Finding alternating sequence in a list of numbers

Please be brutal and treat this as me coding this up for an interview. A sequence of numbers is called a zig-zag sequence if the differences between successive numbers strictly alternate between ...
5
votes
2answers
67 views

Pascal triangle produced for a particular integer K

Please be brutal and let me know what you think of the code below, if written at an interview. Problem: Given an index k, return the kth row of the Pascal's triangle. For example, given k = ...
5
votes
1answer
104 views

Searching in a sorted 2D matrix

If I was at an interview, and wrote this code, what would you think? Please be brutal. Time it took to wrote it: 13 minutes Problem: Write an efficient algorithm that searches for a value in an ...
4
votes
2answers
165 views

Finding the value 'n' in an array that has 'n' or more larger values

Given an unsorted array of integers, you need to return maximum possible \$n\$ such that the array consists at least \$n\$ values greater than or equals to \$n\$. Array can contain duplicate ...