Fidelity International Software Developer Intern Interview Questions and Answers

Round duration - 90 minutes
Round difficulty - Easy

This was face to face interview round. The interviewer was very friendly. He started by asking tell me
something about yourself. I told him about my interest in competitive coding(since I am weak in
probability, I always mentioned competitive coding in my introduction so that the interviewer
asks me coding questions and didn’t move to the probability section).

Q1. 
Maximum Value of an Equation Problem Statement
Given an array/list of integers points containing coordinates (x, y) of N points in a 2D plane, sorted by x-values in non-decreasing order. You need to deter...read more
Ans. 
Find the maximum value of an equation involving coordinates of points in a 2D plane.
• Iterate through all pairs of points and calculate the equation value

• Keep track of the maximum value encountered

• Consider the constraint |xi - xj| ≤ K while calculating the equation value
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Q2. 
Shortest Bridge Problem Statement
Two characters, Tony Stark and Thanos, reside on two separate islands within a 2-D binary matrix of dimensions N x M. Each matrix cell has a value of either 1 (land) or 0...read more
Ans. 
The task is to find the shortest path of transformed 0s that connects two islands in a binary matrix.
• Identify the two islands in the binary matrix.

• Find the shortest path between the two islands by converting 0s to 1s.

• Output the minimal length of the bridge needed to connect the two islands.
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Q3. 
Beautiful City Problem Statement
Ninja plans to visit a city where each house is connected via roads in a binary tree structure. Each level of the tree can have at most 2^K houses. Houses at the same leve...read more
Ans. 
The task is to connect houses at the same level in a binary tree structure using 'next' pointers.
• Traverse the binary tree level by level using BFS

• Connect nodes at the same level using 'next' pointers

• Use a queue to keep track of nodes at each level
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Round duration - 40 minutes
Round difficulty - Medium

The interviewer was very friendly to me. She was praising me for every solution that I provided.

Q1. 
Ninja's Apartment Problem Statement
Ninja plans to build an apartment in the shape of a rectangle. The goal is to determine the length and breadth of this rectangle such that the length is greater than th...read more
Ans. 
Given the area of a rectangle, find the length and breadth such that the length is greater than the breadth and the difference between them is minimized.
• Iterate through possible combinations of length and breadth

• Calculate the area for each combination and check if length is greater than breadth

• Select the combination with minimal difference between length and breadth
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Q2. 
Buy and Sell Stock Problem Statement
Imagine you are Harshad Mehta's friend, and you have been given the stock prices of a particular company for the next 'N' days. You can perform up to two buy-and-sell ...read more
Ans. 
The task is to determine the maximum profit that can be achieved by performing up to two buy-and-sell transactions on a given set of stock prices.
• Iterate through the array of stock prices and calculate the maximum profit that can be achieved by buying and selling at different points.

• Keep track of the maximum profit after the first transaction and the maximum profit overall by considering different combinations of buy a...read more
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Q3. 
Replace Node With Depth Problem Statement
For a given Binary Tree of integers, replace each of its data with the depth of the tree. The root is at depth 0, hence the root data is updated with 0. Replicate...read more
Ans. 
Replace each node in a binary tree with its depth starting from root as 0.
• Traverse the binary tree in inorder fashion and update each node's data with its depth.

• Start with depth 0 for the root node and increment the depth as you go down the tree.

• Handle cases where nodes do not have left or right child by taking -1 in their place.

• Print the inorder traversal of the tree with updated node data representing the depth.
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Round duration - 50 minutes
Round difficulty - Easy

This round was about System Design, Data Structures and Algorithms

Q1. 
Problem: Search In Rotated Sorted Array
Given a sorted array that has been rotated clockwise by an unknown amount, you need to answer Q queries. Each query is represented by an integer Q[i], and you must ...read more
Ans. 
Search for integers in a rotated sorted array efficiently.
• Use binary search to find the pivot point where the array is rotated.

• Based on the pivot point, apply binary search on the appropriate half of the array.

• Return the index of the integer if found, else return -1.

• Example: For input N=5, A=[4, 5, 6, 7, 0, 1, 2], Q=3, Q[i]=[0, 3, 6], output should be 4, -1, 2.
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Round duration - 30 minutes
Round difficulty - Medium

THIS WAS A PUZZLE BASED ROUND

Round duration - 60 Minutes
Round difficulty - Medium

This was a Technical round. About 60 students were shortlisted for this round. There were two interviewers. First, they asked me to introduce myself. Then I was asked some concepts of OOPS. some questions from OS and DBMS. I was asked to write code to reverse a link list on the notepad and share my screen. Then I was asked about my projects and internship. There were some situational questions related to the internship. They asked me what I know about the company.

My interview took place in the morning at around 10:00 a.m. and lasted for about an hour.

Q1. What is the difference between Python and C++?
Ans. 
Python is a high-level, interpreted language known for its simplicity and readability, while C++ is a low-level, compiled language known for its performance and efficiency.
• Python is dynamically typed, while C++ is statically typed.

• Python uses indentation for code blocks, while C++ uses curly braces.

• Python has automatic memory management, while C++ requires manual memory management.

• Python is slower in execution compared...read more
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Q2. 
Reverse Linked List Problem Statement
Given a singly linked list of integers, return the head of the reversed linked list.
Example:
Initial linked list: 1 -> 2 -> 3 -> 4 -> NULL
Reversed link...read more
Ans. 
Reverse a singly linked list of integers and return the head of the reversed linked list.
• Iterate through the linked list and reverse the pointers to point to the previous node instead of the next node.

• Use three pointers to keep track of the current, previous, and next nodes while reversing the linked list.

• Update the head of the reversed linked list as the last node encountered during the reversal process.
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Round duration - 30 Minutes
Round difficulty - Medium

It was a virtual interview and there was just one interviewer. The interviewer was really friendly. First of all, the interviewer introduced himself and also shared some facts about the company. Then he asked me to introduce myself. Then behavioral and situational questions were asked. Then he asked if I was comfortable with relocation. BlackRock has 2 locations that are Gurgaon and Mumbai.

Aptitude test with different sections. Each section had its own time limit. Level - Moderate to difficult

Q1. Introduce yourself
Ans. 
I am a passionate software developer with experience in Java, Python, and web development.
• Experienced in Java and Python programming languages

• Proficient in web development technologies like HTML, CSS, and JavaScript

• Currently pursuing a degree in Computer Science
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Q2. Resume projects
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Q3. 2 DSA questions
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Q4. One SQL Query question
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Q1. MULTIPLE QUESTIONS OF OOPS
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Q2. Program of prime number
Ans. 
A program to find prime numbers within a given range
• Iterate through numbers in the given range

• Check if each number is divisible by any number other than 1 and itself

• If not divisible, it is a prime number
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Q3. Pseudo code of finding ones in a number
Ans. 
Count the number of ones in a given number using pseudo code
• Initialize a count variable to 0

• Iterate through each bit of the number and check if it is 1

• Increment the count if the bit is 1

• Return the count as the result
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Q4. Basic questions of sql and mongodb
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Round duration - 120 minutes
Round difficulty - Medium

A 120-minute online test was conducted on HackerRank which had the following format:
1st Section :
2 Coding questions(30 minutes)
2nd Section :
10 MCQ questions(30 minutes)
3rd Section :
1 Advanced Programming Question(45 minutes)
4th Section :
2 Subjective Questions(15 minutes)
The coding questions and MCQ questions were a bit tricky so you need to manage your time properly and try to solve all the questions correctly..
Technical – included c and c++ output question, os(scheduling, semaphore), dbms(normal form, etc).

 

Q1. 
Consecutive Sum Representation of a Number
Find the number of ways the given number 'N' can be expressed as the sum of two or more consecutive natural numbers.
Example:
Input:
N = 9
Output:
2
Explan...read more
Ans. 
Find the number of ways a given number can be expressed as the sum of two or more consecutive natural numbers.
• Use a sliding window approach to iterate through all possible consecutive sums.

• Keep track of the sum of the current window and adjust the window size accordingly.

• Count the number of valid consecutive sum representations of the given number.

• Example: For N = 9, valid representations are 2 + 3 + 4 and 4 + 5, so th
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Q2. 
Count Pairs with Given Sum
Given an integer array/list arr and an integer 'Sum', determine the total number of unique pairs in the array whose elements sum up to the given 'Sum'.
Input:
The first line c...read more
Ans. 
Count the total number of unique pairs in an array whose elements sum up to a given value.
• Use a hashmap to store the frequency of each element in the array.

• Iterate through the array and for each element, check if (Sum - element) exists in the hashmap.

• Increment the count of pairs if the complement exists in the hashmap.
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Round duration - 45 minutes
Round difficulty - Medium

interview started with a typical tell me about yourself question. The interviewer was nice and friendly. 

He asked me to explain a little about my projects (only basics).
Which all data structures you know and my favourite data structure. I replied with a linked list.
He asked the difference between array and linked list, time complexities of insertion, deletion, etc. in both of them. Then he asked about sorting an array, different algorithms, and their time complexities.
How would you sort a linked list? How would you find the middle of the linked list in one pass? How would you merge two linked lists (I had to write code for the same)?
Then he asked how would you be able to manage the business and finance decisions at GS.
Tell me an incident when you had the chance to display your leadership skills.
Lastly, I was allowed to ask questions from the interviewer.

Q1. 
Cousin Nodes in a Binary Tree
Determine if two nodes in a binary tree are cousins. Nodes are considered cousins if they are at the same level and have different parents.
Explanation:
In a binary tree, e...read more
Ans. 
Determine if two nodes in a binary tree are cousins based on level and parent criteria.
• Traverse the tree to find the levels and parents of the given nodes.

• Check if the nodes are at the same level and have different parents.

• Return 'YES' if the nodes are cousins, 'NO' otherwise.
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Round duration - 45 minutes
Round difficulty - Medium

This round was relatively short and mostly consisted of coding (on hackerrank’s codepair platform)

The interviewer asked me about my previous interview and what all questions were asked in it.
Then there was a discussion about my projects and the technologies used in them. How would you deploy an application and what happens in the process of entering a keyword in the browser and loading your requested page? 
He asked me to write the code for finding the middle of a linked list in one pass.
After that, I had to write the code for the implementation of a queue. I first discussed the approaches with him using array and linked lists for some time. They wrote the code using a linked list by taking head and tail pointer.
He was satisfied with it and the round ended with me asking him the questions I had.

Q1. 
Middle of a Linked List
You are given the head node of a singly linked list. Your task is to return a pointer pointing to the middle of the linked list.
If there is an odd number of elements, return the ...read more
Ans. 
Return the middle element of a singly linked list, or the one farther from the head if there are even elements.
• Traverse the linked list with two pointers, one moving twice as fast as the other

• When the fast pointer reaches the end, the slow pointer will be at the middle

• If there are even elements, return the one that is farther from the head node

• Handle edge cases like linked list of size 1 or empty list
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Round duration - 90 minutes
Round difficulty - Medium

This test was conducted on the Hackerrank platform, it was divided into 6 sections which contained a total of 66 questions with an overall time limit of 90 minutes, There was video proctoring, and changing sections were allowed.
The sections were-

Numerical Computations — 8 questions
Numerical Reasoning -12 questions
Comprehension — 10 questions
Abstract Reasoning — 12 questions
Diagrammatic Reasoning — 12 questions
Logical Reasoning — 12 questions

Q1. 
Convert a Number to Words
Given an integer number num, your task is to convert 'num' into its corresponding word representation.
Input:
The first line of input contains an integer ‘T’ denoting the number o...read more
Ans. 
Convert a given integer number into its corresponding word representation.
• Implement a function that takes an integer as input and returns the word representation of the number in English lowercase letters.

• Break down the number into its individual digits and convert each digit into its corresponding word form.

• Handle special cases like numbers between 10 and 19, multiples of 10, and numbers with zeros in between.

• Concaten...read more
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Round duration - 45 Minutes
Round difficulty - Easy

The interview started at 12 in the noon.
The interviewer seemed very cheerful. He began by greeting and asked me for a quick introduction.
Then he talked about the various projects I have mentioned in my resume and what further improvements I was going to make in my projects. Further he started asking questions on fundamentals of Data Structures and Algorithms, few questions on operating syatem and gave a problem statement on DSA.

Q1. 
Pair Sum Problem Statement
You are provided with an array ARR consisting of N distinct integers in ascending order and an integer TARGET. Your objective is to count all the distinct pairs in ARR whose sum...read more
Ans. 
Count distinct pairs in an array whose sum equals a given target.
• Use two pointers approach to iterate through the array and find pairs with sum equal to target.

• Keep track of visited elements to avoid counting duplicate pairs.

• Return -1 if no such pair exists with the given target.
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Round duration - 120 minutes
Round difficulty - Easy

This round was held in the evening at 6 o'clock on Hackerrank. It had coding questions: easy, medium, and hard level and MCQ's ( 1 minute for each MCQ). Negative marking was also there

Q1. 
Excel Column Number Problem Statement
Given a column title as it appears in an Excel sheet, return its corresponding column number.
Example:
Input:
"AB"
Output:
28
Explanation:
Column title "AB" co...read more
Ans. 
Convert Excel column title to corresponding column number
• Iterate through the characters in the column title from right to left

• Calculate the corresponding value of each character using its position in the alphabet

• Multiply the value by 26 raised to the power of its position from right

• Sum up all the values to get the final column number
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Q2. 
Climbing the Leaderboard Problem Statement
In a game leaderboard, scores determine rankings where the highest score gets rank 1. Players with identical scores share the same rank, followed by the next ran...read more
Ans. 
Implement a function to determine a player's leaderboard rank for each game score.
• Iterate through the game scores and compare them with the leaderboard scores to determine the rank.

• Handle cases where players have identical scores by assigning them the same rank.

• Ensure the leaderboard scores are in descending order and game scores are in ascending order.

• Return the ranks for each game score in an array.
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Round duration - 30 minutes
Round difficulty - Easy

This was an interview round ( technical round) that was held on video-call and a coding platform was also shared. The interviewer was very friendly with me . She was praising me on every solution that I provided.

Q1. 
Flatten The Multi-Level Linked List
You are given a multi-level linked list of N nodes, where each node can have two pointers: next and child. Flatten this multi-level linked list into a singly linked lis...read more
Ans. 
Flatten a multi-level linked list into a singly linked list and return the head of the flattened list.
• Traverse the linked list in level order

• Use a stack to keep track of nodes with child pointers

• Merge the child nodes into the main list
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Q2. 
The Celebrity Problem
Imagine there are 'N' people at a party, each assigned a unique ID from 0 to N-1. A celebrity at the party is a person who is known by everyone but knows no one else.
Problem Statem...read more
Ans. 
Identify the celebrity at a party where one person knows everyone but is not known by anyone.
• Use a two-pointer approach to eliminate non-celebrities.

• Start with two pointers at the beginning and end, move them based on 'knows' results.

• If A knows B, A cannot be the celebrity; move A pointer. If A does not know B, B cannot be the celebrity; move B pointer.

• Repeat until only one person remains, check if this person is known...read more
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Round duration - 35 minutes
Round difficulty - Easy

This was an interview round ( technical round) that was held on video-call and a coding platform was also shared. The interviewer was very friendly with me . She was praising me on every solution that I provided.

Q1. 
Design a HashSet
Create a HashSet data structure without using any built-in hash table libraries.
Functions Description:
1) Constructor: Initializes the data members as required.

2) add(value): Inserts...read more
Ans. 
Design a HashSet data structure with add, contains, and remove functions.
• Implement a HashSet using an array of linked lists to handle collisions.

• Use a hash function to determine the index in the array for each element.

• For add function, check if the element already exists before inserting.

• For contains function, search for the element in the corresponding linked list.

• For remove function, find and remove the element from ...read more
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Round duration - 20 minutes
Round difficulty - Easy

Online HR+Technical Round .