Software Developer Mock Interview

Master 30 Software Developer interview questions covering algorithms, system design, and coding challenges.

WRITTEN BY TOM DUSHAJ
QUESTION 2 OF 30

What method do you use to find the missing number in an integer array of 1 to 100?

I always look at different ways to solve a problem or find a solution. A step-by-step process is a simple solution that I use to find a missing number in an integer array. Let me demonstrate:

Step 1: Create an array with a number like 10001 with all zeros
Step 2: Decrease the value corresponding to the input value (A). An example would be if we have a value of 200, we will decrease that value.
Step 3: Read list (B) value and increase that value. At this point, the elements of list A would be lost, resulting in the array having performed this operating will then be positive.
Step 4: Print all the indexes of the array with a value greater than the number 0.

When it comes to interview questions about finding missing numbers in an integer, that tells me that the interviewer has a specific type of role in mind for a candidate. More than likely, they are looking for an analytical thinker who can solve problems relatively easily. Let me demonstrate. Let's say I have an array number from 1 to 100. These are just random numbers for now. In a sorted array, you can compare whether a number is equal to the expected next number or not. Alternatively, you can also use the BitSet method in Java to solve this problem as well. A BitSet solution is more general, as you can use it to find more than one missing value on an integer array. Take your time to think about how you will respond to these types of questions because the interviewer is testing your ability to process and come up with an answer.

"Having many tools at my disposal, I find that a Java solution is the best way to solve this problem. I would typically write a program to find the missing number in an array in Java, C#, or another language. The method I use is to find missing elements in an area of 100 integers, which contains numbers between 1 and 100. Looking at this problem from a high level, this can easily be solved by calculating the sum of the series using n(n1)/2 to solve this problem. It's a quick and efficient way to do it, but keep in mind that it cannot be used if the array contains more than one number or if the array contains duplicates. Some of these solutions might require you to calculate the sum of numbers and then subtract that from the actual sum to arrive at the correct answer."

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30 Software Developer Interview Questions & Answers

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01 Explain how duplicates are removed from an array without using a library? TECHNICAL 02 What method do you use to find the missing number in an integer array of 1 to 100? TECHNICAL 03 Tell me how you find duplicate numbers in an array in Java containing multiple duplicates? TECHNICAL 04 How do you find the starting node of a cycle if a link contains a cycle? TECHNICAL 05 Based on your experience, what's the best way to find a node that begins with two single link lists? TECHNICAL 06 How do you approach implementing an LRU Cache in your favorite programming language? TECHNICAL 07 What is your experience with implementing a Binary Search Algorithm without recursion? TECHNICAL 08 Can you walk me through the meaning behind a Depth First Search Algorithm for a binary tree? TECHNICAL 09 Describe how do you implement an insertion sort algorithm, and what's the easiest way to do it? TECHNICAL 10 Tell me the difference between a Comparison and Non-Comparison Sorting Algorithm? TECHNICAL 11 Can you list for me the important categories of software development? TECHNICAL 12 Describe at a high level what the software development life cycle process is. TECHNICAL 13 What is verification and validation, and why it is important? TECHNICAL 14 As a software developer, explain the meaning of debugging, and why it's used? TECHNICAL 15 Do you have a preferred language that you like to write programming algorithms? OPERATIONAL 16 What is software scope, and what does the process involve? OPERATIONAL 17 How would you define software configuration management? OPERATIONAL 18 What is your opinion on a feasibility study, and when should it be done? OPERATIONAL 19 As part of software development, were you involved with working on functional and non-functional requirements? OPERATIONAL 20 Talk about the differences between structured English and Pseudo Code? TECHNICAL 21 Making a comparison, how would you differentiate between Quality Assurance and Quality Control? OPERATIONAL 22 What software development process do you prefer to use? OPERATIONAL 23 I’ve heard applications referred to as both software and programs. Which terminology do you use, and how do these differ? GENERAL 24 What are some of the types of development projects you have worked on in your past positions? GENERAL 25 What are some of the software design patterns that you use, and in what situations do you use them? OPERATIONAL 26 Can you describe a challenging software development project you recently completed and the results? GENERAL 27 Are you familiar with Agile and Waterfall? Which of these software development methodologies do you prefer? OPERATIONAL 28 What are some of the QA processes you are familiar with and have worked with in the past? OPERATIONAL 29 What are some of the testing and debugging processes you use in your software development? OPERATIONAL 30 How much do you know about object-oriented programming? TECHNICAL
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Tom Dushaj
30 QUESTIONS & ANSWERS · SOFTWARE DEVELOPER
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