OpenGenus IQ: Learn Algorithms, DL, System Design (Page 144)

do while loop in Java

A do-while loop is similar to a while loop, except the fact that it is guaranteed to execute at least one time. The do-while loop checks its condition at the bottom of the loop after one time execution of do and hence, is an exit control loop. It is slower than for and while loops in Java

Software Engineering

while loop in Java

A while loop is an entry controlled control flow statement that allows code to be executed repeatedly based on a given condition. In Java, while loop is widely used. On benchmarking the performance, we see that while loop is slower than for loop but is two times faster than do while loop.

Data Structures

Binomial Heap

Binomial Heap is an extension of Binary Heap that provides faster union or merge operation together with other operations provided by Binary Heap. A Binomial Heap is a collection of Binomial trees. Binomial Heap is used to implement priority queues.

Data Structures

Priority Queue

Priority queue is an abstract data type which is like a queue or stack data structure with each element having a priority assigned to it. In priority queue, an element with highest priority assigned is served first, if two elements have same priority then they are served according to enqueue order

Java

Postfix (i++) vs Prefix (++i) increment in Java

i++ is known as postfix increment operation while ++i is known as prefix increment operation. We compare these two operations based on Use/ Program flow, Compiler instruction and Benchmark. We demonstrate that ++i is significantly faster than i++ in Java.

Java

i++ vs i=i+1 in Java

Often, i++ and i=i+1 are considered to be same statements but in Java, both statements work differently internally. We will take a look at The compiler instructions used, Typecasting along with the operations and benchmarking the two operations. We see that i=i+1 is always faster than i++.

Java

for loop in Java

for loop is an entry controlled loop that is widely used in Java programming language. Loops are used to repeat a particular coding task where each repetition follows a particular pattern which can be incorporated in a code. We provided several Java examples to demonstrate the concept

Python

Reading and Writing Text Files in Python

This post will cover how to work with text files specifically in Python. We covered Opening a file, Reading a file: read() and readlines(), Writing to files, keeping track of pointers: tell() and seek(), Closing a file and File attributes

Python

if else statement in Python

We will take a deep look into if else, else if (elif), nested if else and the possible condition statements used in if else in Python. if else is a program control statement and is widely used in almost all programming languages

C++

Classes and Objects in C++

In C++, a class is a mechanism for creating user-defined data types. A class is used to specify the form of an object and it combines data representation. The variables inside class definition are called as data members and the functions are called member functions.

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.