OpenGenus Tech Review Team

C++

Scopes in C++

Scope is defined as the extent to which something can be worked with (or a scope is a region of the program ). In C++, there are 9 types: Global scope, Local scope, Namespace scope, Class scope, Statement scope, Function scope, Function parameter scope, Enumeration scope and Template parameter scope

Algorithms

Sleep Sort

Sleep Sort is time-based sorting technique. We create different threads for each individual element present in the array. The thread is then made to sleep for an amount of time that is equal to value of the element for which it was created. Time complexity is O(NlogN + max(input))

Data Structures

Implementing Stack using queues in two ways

A stack is based on the principle of Last-in-First-Out(LIFO). It is commonly used abstract data type with two major operations, namely pop and push. Push() and pop() are carried out in the topmost element, which is the item most recently added to the stack. Push operation adds an element to stack

C++

Priority Queue in C++ STL

Priority queue in the STL of C++ is a dynamically resizing container to implement the special case of priority queye under the queue data structure. It is a sequential linear container. The top element of the priority queue is the greatest with all elements arranged in non-increasing order.

C++

Queue in C++ STL

Queue in the STL of C++ is a dynamically resizing container to implement the queue data structure. It is a sequential linear container which follows the First In First Out(FIFO) arrangement. We explore the various functions like empty, size, swap, emplace, front, back, push and pop operations

Algorithms

Distance between two points in 2D space

Distance between two points is calculated by creating a right-angled triangle using the two points.The line between the two points is the hypotenuse (the longest side, opposite to the 90° angle). We used the Distance formula derived from Pythagorean theorem with a time complexity of O((log N)^2)

Algorithms

Area of Polygon: Shoelace formula

Given coordinates of vertices of polygon, Area of Polygon is calculated using Shoelace formula described by Mathematician and Physicist Carl Friedrich Gauss where polygon vertices are described by their Cartesian coordinates in the Cartesian plane. The time complexity is O(N) with O(1) space

Data Structures

Stack

Stack serves two principal operations: push, which adds an element to the collection, and pop, which removes the most recently added element that was not yet removed. We have covered functions like top, isFull, isEmpty, peek, pop, push and given an implementation example

Python

Tuple in Python

Tuples in Python are used to hold together multiple objects. Tuples are defined by specifying items separated by commas within an optional pair of parentheses. Any set mutiple comma-separated symbols written default to tuples. Tuples are immutable

C++

Virtual Function in C++

A virtual function in C++ is a member function which is declared within a base class and is overriden by a derived class. When you refer to a derived class object using a pointer or a reference to the base class, you can call a virtual function for that object and execute the derived class function

C++

Vector in C++

Vector is a sequence container that can store elements, but its size can change dynamically (C/C++ array’s size do not change dynamically). We can store int, string, float elements, depending on how we initialize the vector.

Algorithms

Extended Euclidean Algorithm

We will demonstrate Extended Euclidean Algorithm. We will see how you can calculate the greatest common divisor in a naive way which takes O(N) time complexity which we can improve to O(log N) time complexity using Euclid's algorithm. Extended Euclidean Algorithm takes O(log N) time complexity

C++

Inheritance in C++

Inheritance in C++ allows us to define a class in terms of another class, which makes it easier to create and maintain an application. This provides an opportunity to reuse the code functionality. Single, multiple, hierarchical, multilevel, multipath and hybrid inheritance is supported in C++

C Programming

continue statement in C

The continue statement is a jump statement in C. It is another one of the jump statements like the break statement as both the statements skip over a part of the code. But the continue statement is somewhat different from the break statement. It forces the next iteration of the loop to take place

C++

Namespace in C++

Namespaces in C++ allow us to group named entities that otherwise would have global scope into narrower scopes, giving them namespace scope. This allows organizing the elements of programs into different logical scopes referred to by names.

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

C++

Unique_ptr in C++

A unique_ptr is like a normal pointer, except the fact that it "owns" the object to which it points, as mentioned above. The word "unique" in the title refers to the fact that at a time, only one unique_ptr can point to a given object and the object is destroyed when the pointer is destroyed.

Algorithms

Sieve of Atkin

Sieve of Atkin is an algorithm used to find all prime numbers upto a given number (say N) and does so in O(N) time complexity. With a modified version with enumerating lattice points variation, the time complexity goes to O(N / log log N). It is computationally efficient than Sieve of Eratosthenes

Data Structures

Union Find (Disjoint Set)

A Union Find data structure (also called disjoint-set) is a data structure that keeps track of elements partitioned into a number of disjoint subsets. It provides near-constant-time operations to add new sets, to merge existing sets, and to determine whether elements are in the same set.

C++

Program Flow control in C++

The flow of control jumps from one part of the program to another, depending on calculations performed in the program. Program statements that cause such jumps are called control statements. We have covered for, while, do while loop, if else, switch, break, continue, goto and functions.

C++

Friend Function in C++

C++ allows a mechanism, in which a non-member function has access permission to the private members of the class. This can be done by declaring a non-member function friend to the class whose private data is to be accessed. The friend is a keyword.

Software Engineering

Understand Inheritance in depth

Inheritance is the process by which objects of one class acquire the properties of objects of another class. It supports the concept of hierarchical classification. The different types of inheritance are single, multilevel, hierarchical, hybrid, multipath and multiple inheritance

C++

Operator Overloading in C++

Operator overloading is an important concept in C++. It is a type of polymorphism in which an operator is overloaded to give user defined meaning to it. Overloaded operator is used to perform operation on user-defined data type. We give examples of unary ++, bitwise + and arithmetic + operators

Algorithms

Area of Triangle: Heron's formula

We take a look at Heron's formula which will enable us to calculate the area of any triangle given the length of the three sides of that triangle. The advantage is that the area is calculated using arithmetic operations and hence, the time taken can be assumed to be constant,

Machine Learning (ML)

Bias in Machine learning

Bias is an constant parameter in the Neural Network which is used in adjusting the output. Therefore Bias is a additional parameter which helps the model so that it can perfectly fit for the given data. It is also known as bias nodes, bias neurons, or bias units