Interview Problems on Array

Array Interview Questions [MCQ with answers]

This is the list of Interview Questions based on Array Data Structure. You must practice these Multiple Choice Questions. This will help you master Array Coding Questions for Interviews at companies like Google and Microsoft.

Algorithms

Boyer Moore majority vote algorithm [Majority Element]

Boyer Moore voting algorithm is used to find the majority element among the given sequence of elements which occurs more than N/2 times, in linear time complexity and constant space complexity.

Software Engineering

Process of deleting an array in C++

We have explained how to delete an array or delete an element in an array in C++. We can covered the case of static and dynamic memory allocated array along with the basics of array.

Algorithms

Move negative elements to front of array

This article focuses on the algorithm to move the negative elements of an array to the front. This can be solved by the two-pointer approach.

Algorithms

Bit Array [Explained with example]

Bit Array is a data structures that compactly stores Boolean values or bits in the form of an array. The bits can be 0 or 1 only. Each bit in the bit array is independent.

Algorithms

Least frequent element in an array

Given an array of N elements, our task is to find the least frequent element present in it. In this article, we are going to talk about 3 methods to solve this problem along with their implementation.

List of Mathematical Algorithms

Equilibrium Index: Find index such that sum of left sub-array = right sub-array

For a given array, we need to find an index such that sum of left sub-array = right sub-array also called the Equilibrium Index. We solve this using brute force approach O(N^2) and using prefix array in linear O(N) time.

Algorithms

Finding LCM of an array of numbers

Find the LCM of the given array of positive numbers. We have explored 2 approaches: one using GCD and other without using GCD.

Algorithms

Finding 2 elements with difference k in a sorted array

This article discusses how to check the existence of and find 2 elements with difference k in sorted array. We have explored 3 approaches and solved it in linear time O(N).

Algorithms

Next Larger / Smaller element in Array (using Monotonic Queue)

In this problem, we are given an array and our task is to find the next larger/ smaller element for each element in the array. We have covered brute force approach and Monotonic Queue.

Algorithms

3 Sum problem (Triplets with given Sum)

Given an array, we need to find if there is a triplet in the array whose sum is equal to a given value. If such a triplet is present, we need to print it and return true. Else, return false.

Data Structures

Implementing a Stack using an Array and Linked list

Stack is a linear data structure following LIFO (Last in First out) order and can be implemented using Array or Linked List as an internal data structure.

Algorithms

Finding the Largest Element in an Array

We are given an integer array of size N or we can say number of elements is equal to N. We have to find the largest/ maximum element in an array. The time complexity to solve this is linear O(N) and space complexity is O(1).

Software Engineering

Three dimensional (3D) array in C

A 3D array is a multi-dimensional array (array of arrays). A 3D array is a collection of 2D arrays. We have explored 3D arrays in C in depth from defining such array along with basic operations.

Software Engineering

Two dimensional (2D) array in C

In this article, we have explored 2D arrays in C including declaring 2D array, calculating size, inserting elements and updating 2D array, convert 3D array to 2D array and using malloc to define 2D arrays in C.

Data Structures

Dynamic Array

Dynamic Array solves the problem of array where the size needs to fixed beforehand. On average, dynamic array achieves same performance as an array by using resize operation.

Algorithms

Multiple array range increments in linear time O(N)

Given an array a containing N integers, we perform M queries. Each query has three values START, END and a value D. For each query, the problem is to increment the values from the start to end index(both inclusive) in the given array by the given value d. An efficient algorithm takes O(N+M) time

Python

Create arrays in Numpy

Numpy functions that we have covered are arange(), zeros(), ones(), empty(), full(), eye(), linspace() and random(). Creating and managing arrays is one of the fundamental and commonly used task in scientific computing. Numpy is a Python library which adds support for several mathematical operations