Fidelity Investments interview questions
Online test → Technical → HR
DSA
Showing 34 of 75 reported in this area
Given Q queries each with inputs L and R, find all composite numbers in the inclusive range [L, R].
Find common elements in three sorted arrays.
Explain AVL trees and their operations
Print all permutations of a given string.
General data structures and algorithms questions
Write the algorithm for Floyd-Warshall algorithm
Convert a prefix expression to postfix using a stack
Solve and explain a coding problem related to strings.
Find the longest palindromic substring in a given string.
Explain how Hash Maps work and how collisions are handled.
Write an algorithm for a problem using Dynamic Programming
Find the maximum size subarray with equal number of 0s and 1s.
Explain or write an algorithm for path finding using BFS or DFS
Write the algorithm or logic for a given problem in your own words.
Explain the algorithm or pseudocode to solve a problem using backtracking.
Explain and analyze sorting algorithms, including their time and space complexities
Implement the Floyd-Warshall algorithm to find all-pairs shortest paths in a graph.
Given a number N, return the Kth nearest prime number based on absolute difference from N.
Write an algorithm to solve a real-life problem using standard computer science algorithms
Given an array and a target sum, find the pair of elements whose sum is closest to the target.
Form the largest even number possible using at most one swap operation on the digits of a given number.
An array consists of 0s and 1s. Find the length of the longest subarray containing equal number of 0s and 1s.
Find the area of the largest triangle that can be formed inside a rectangle and round it to the nearest integer
Given a 2D n x n matrix, print the sum of those diagonal elements whose count is greater than 3 in the entire matrix
Explain Greedy Algorithms and Dynamic Programming. What is Quick Sort and Merge Sort? Compare their efficiency and use cases.
Given an integer array of size N, print all even numbers in non-decreasing order first, followed by all odd numbers in ascending order.
Given an array and an integer K, partition the array into K subarrays such that the maximum subarray sum is minimized. Return this minimum possible value.
How would you find the second largest element in an unsorted array? How would you find the nth largest element? What is the time complexity in both cases?
Given two strings, sort the first string based on the order of character occurrences in the second string. Characters absent in the second string should appear at the end in their original relative order.
Given a matrix, convert it into a square matrix by appending 1s where required, then compute the sum of diagonal elements such that a diagonal element is counted only if it appears an odd number of times outside the diagonal.
Given N villages arranged in a circular pattern with distances between consecutive villages and an energy drink at each village, determine the starting village index such that a traveler starting with zero energy can complete the full circle.
Alice and Bob are given some number of chocolates. When Alice has more chocolates, she leaves chocolates in the box equal to the number Bob has, and vice versa. This continues until both have equal chocolates or one has zero. Find the number of times chocolates are left in the box.
Write an algorithm to find the maximum sum submatrix in a 2D array.
Given an elevation map, compute how much water it can trap after raining.
CS fundamentals
Showing 18 of 74 reported in this area
Explain the difference between multithreading and multiprocessing.
Explain the difference between JavaScript and TypeScript.
Explain inheritance and the Diamond Problem
Write pseudocode for the Floyd Warshall Algorithm.
Predict the output of given C++ or Java code snippets
What is a friend function and what is binding in C++?
What is Blockchain and what are its potential applications?
Explain the Diamond Problem in Object-Oriented Programming (Java).
What is an RDBMS and what are some algorithms used in data mining?
Given a table, write an SQL query to fetch specific information using a self-join.
Explain or apply the Floyd–Warshall algorithm to solve an all-pairs shortest path problem.
How would you check whether a binary string has been transmitted correctly without any errors?
Write a program to extract data from two tables connected by a foreign key using PL instead of SQL
Given a recursive code snippet, determine its output or identify whether it produces a compilation or runtime error.
Explain object-oriented programming concepts such as inheritance, polymorphism, encapsulation and abstraction in C++/Java
Given an employee table with attributes (emp_id, emp_name, manager_id, etc.), find an employee named "Akash" who is not a manager
What is the difference between Machine Learning and Deep Learning? Explain activation functions, vanishing gradient problem, and Leaky ReLU.
Explain normalization, difference between triggers and cursors, RDBMS vs NoSQL databases, types of joins, primary key vs composite key, and indexing.
Aptitude
Showing 3 of 12 reported in this area
Given a number N, count how many numbers i in the range (1, N) satisfy (3 * i + 1) > N.
Given the 2nd and 3rd elements of an arithmetic progression (AP), find the nth element.
English language and verbal ability questions
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Behavioural
Showing 3 of 7 reported in this area
Have you ever been in charge of a team or a project?
How do you work as part of a team or as an individual?
Explain a technical concept to someone who has never used a computer.
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Puzzles
Showing 1 of 5 reported in this area
Puzzle: There are socks of 20 different colors such that there are 1 pair of color c1, 2 pairs of c2, ..., up to 20 pairs of c20. What is the maximum number of socks you need to pick to guarantee at least one matching pair of the same color?
System design
1 questions reported in this area
How would you design and implement a distributed cache for a large-scale application?
Showing 60 of 119 questions. Ranked by how often the same question came back across reports.
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What questions does Fidelity Investments ask?
Candidate interview reports most often cover DSA (43%) and CS fundamentals (43%).
How many rounds does Fidelity Investments interview have?
Candidate interview reports show an average of 3.1 rounds per experience, with a typical sequence of Online test → Technical → HR. Individual interview paths can vary.
Is the Fidelity Investments interview hard?
Among questions with a reported difficulty, the mix is easy 50%, medium 46%, hard 4%.