10+ FactSet Software Engineer Interview Questions and Answers

Find an odd occurring number among even occurring numbers.

• Use XOR operation to cancel out even occurring numbers and get the odd occurring number.

• Iterate through the array and XOR each element with the result variable.

• The final result will be the odd occurring number.

Find total number of k element with given avg in an array in minimum time complexity.

• Use sliding window technique to traverse the array in O(n) time complexity.

• Maintain a sum variable to keep track of the sum of elements in the window.

• If the sum of elements in the window is equal to k times the given avg, increment the count.

• Move the window by subtracting the first element and adding the next element in the array.

Printing non-boundary elements of a binary tree

• Traverse the tree in any order (preorder, inorder, postorder)

• Check if the current node is not a boundary node (not the first or last node in its level)

• If it is not a boundary node, print its value

• Recursively traverse its left and right subtrees

Finding pairs in an array with a given sum.

• Iterate through the array and for each element, check if the difference between the given sum and the element exists in the array.

• Use a hash table to store the elements of the array and their indices for faster lookup.

• If there are multiple pairs with the same sum, return any one of them.

• If no pair is found, return null or an empty array.

Print the spiral order of a binary tree and matrix.

• For binary tree, use level order traversal and alternate direction for each level.

• For matrix, use four pointers to traverse in spiral order.

• Example for binary tree: 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7 -> 8 -> 9

• Example for matrix: 1 2 3 4 -> 8 7 6 5 -> 9 10 11 12 -> 16 15 14 13

Given an array and target, find the index pair of elements the sum becomes target.

• Use a hash table to store the difference between target and current element

• Check if the difference exists in the hash table

• Return the indices of the current element and the difference

Data structure is a way of organizing and storing data in a computer so that it can be accessed and used efficiently.

• Data structures are used to manage large amounts of data efficiently.

• They provide a way to organize data in a way that makes it easy to access and manipulate.

• Examples of data structures include arrays, linked lists, stacks, queues, trees, and graphs.

A linked list is a linear data structure where each element is a separate object with a pointer to the next element.

• Consists of nodes that contain data and a pointer to the next node

• Can be singly or doubly linked

• Used for dynamic memory allocation, implementing stacks and queues

• Example: Singly linked list - 1 -> 2 -> 3 -> null

• Example: Doubly linked list - null <- 1 <-> 2 <-> 3 -> null

Implementing hashmap using OOPS involves creating a class with key-value pairs and methods for adding, retrieving, and deleting entries.

• Create a class with private data members for storing key-value pairs

• Implement methods for adding a key-value pair, retrieving a value by key, and deleting a key-value pair

• Use hashing function to map keys to indices in an array for efficient retrieval

• Handle collisions by using techniques like chaining or open addressing

Prototyping in JavaScript allows for quick and easy creation of new objects and functions.

• Prototyping allows for inheritance and sharing of properties and methods.

• New objects can be created using the 'new' keyword and the prototype of an existing object.

• Functions can also be prototyped to add new methods or properties.

• Example: function Person(name) { this.name = name; } Person.prototype.greet = function() { console.log('Hello, my name is ' + this.name); } var john = new Perso...read more