All Hard Articles

Count of submatrix with sum X in a given Matrix

Given a matrix of size N x M and an integer X, the task is to find the number of sub-squares in the matrix with… Read More

prefix-sum

submatrix

Competitive Programming

DSA

Dynamic Programming

Mathematical

Matrix

Searching

Cost and Schedule Estimating Process

The cost and schedule estimation process helps in determining number of resources to complete all project activities. It generally involves approximation and development of costing… Read More

Software Engineering

PPP Full Form

PPP stands for Point-to-Point Protocol. PPP is Windows’ default Remote Access Service (RAS) protocol and is Data Link Layer (DLL) protocol used to encapsulate higher… Read More

Picked

Computer Networks

Full Form

Maximal independent set from a given Graph using Backtracking

Given an undirected graph with V vertices and E edges, the task is to print all the independent sets and also find the maximal independent… Read More

Algorithms

Backtracking

C++ Programs

Competitive Programming

Data Structures

DSA

Graph

P-value in Machine Learning

P-value helps us determine how likely it is to get a particular result when the null hypothesis is assumed to be true. It is the… Read More

Machine Learning

Difference between process.nextTick() and setImmediate() Methods

To understand the difference between process.nextTick() and setImmediate() methods, we first need to understand the working of Node.js Event Loop. What is Node.js Event Loop?… Read More

Node.js-Methods

Picked

Node.js

Web Technologies

Having clause in MS SQL Server

In this article, we will be discussing having clause in MS SQL Server. There are certain instances where the data to be extracted from the… Read More

DBMS-SQL

mysql

DBMS

SQL

turtle.stamp() function in Python

The turtle module provides turtle graphics primitives, in both object-oriented and procedure-oriented ways. Because it uses tkinter for the underlying graphics, it needs a version… Read More

Python-turtle

Python

Quick Sort using Multi-threading

QuickSort is a popular sorting technique based on divide and conquer algorithm. In this technique, an element is chosen as a pivot and the array… Read More

Java-Multithreading

Quick Sort

Divide and Conquer

DSA

Java

Sorting

Construct the smallest possible Array with given Sum and XOR

Given two positive integers S and X which represents the sum and Bitwise XOR of all the elements of an array arr[]. The task is… Read More

Bitwise-XOR

Algorithms

Arrays

Bit Magic

Competitive Programming

DSA

Greedy

Count of N-digit numbers with absolute difference of adjacent digits not exceeding K

Given two integers N and K, the task is to find the count of N-digit numbers such that the absolute difference of adjacent digits in… Read More

interview-preparation

number-digits

prefix-sum

Combinatorial

Competitive Programming

DSA

Dynamic Programming

Mathematical

Sorting boundary elements of a matrix

Given a matrix mat[][] of size M*N, the task is to sort only the border elements of the matrix in the clockwise direction and print… Read More

Sorting Quiz

DSA

Matrix

Pattern Searching

Python

Python Programs

Sorting

The Skyline Problem | Set 2

Given n rectangular buildings in a 2-dimensional city, computes the skyline of these buildings, eliminating hidden lines. The main task is to view buildings from… Read More

Algorithms

Competitive Programming

Data Structures

DSA

Sorting

Count of natural numbers in range [L, R] which are relatively prime with N

Given three integers N, L, and R. The task is to calculate the number of natural numbers in the range [L, R] (both inclusive) which… Read More

array-range-queries

Maths

Natural Numbers

number-theory

Prime Number

Competitive Programming

DSA

Mathematical

What is Git-Ignore and How to Use it?

There are various types of files we might want the git to ignore before committing, for example, the files that are to do with our… Read More

GitHub

Git

How to check if string contains only digits in Java

Given string str, the task is to write a Java program to check whether a string contains only digits or not. If so, then print… Read More

Java-Character

java-regular-expression

Java-String-Programs

number-digits

regular-expression

DSA

Java Programs

Pattern Searching

School Programming

Strings

Smallest number greater than Y with sum of digits equal to X

Given two integers X and Y, find the minimal number with the sum of digits X, which is strictly greater than Y. Examples: Input: X… Read More

number-digits

school-programming

Algorithms

Competitive Programming

DSA

Greedy

Mathematical

School Programming

Strings

Component Based Diagram

Component Diagrams are used to show code modules of a system in Unified Modeling Language (UML). They are generally used for modeling subsystems. It represents… Read More

Software Engineering

Maximum sum subarray of size range [L, R]

Given an integer array arr[] of size N and two integer L and R. The task is to find the maximum sum subarray of size… Read More

prefix-sum

sliding-window

subarray

subarray-sum

Arrays

DSA

Greedy

Searching

Python – Join Tuples if similar initial element

Sometimes, while working with Python tuples, we can have a problem in which we need to perform concatenation of records from the similarity of initial… Read More

Python tuple-programs

Python

Python Programs