Algorithms that run our Universe

Different Basic Sorting algorithms. Know when to use which one and Ace your tech interview!

We have covered the basic ideas of the basic sorting algorithms such as Insertion Sort and others along with time and space complexity and Interview questions on sorting algorithms with answers.

Algorithms

Designing a Binary Search Tree with no NULLs

A Binary Search Tree (BST) is usually implemented using NULLs in C or C++. This article explores an alternative approach of using placeholder nodes. Here the Binary Search Tree will be implemented in C++.

Data Structures

Optimizations in Union Find Data Structure

Union find data structure is also called disjoined set data structure as it a collection of disjoined subsets. There are different optimizations such as union by rank/ size, path compression and much more.

Algorithms

NP Hard problems

We have covered the basics of NP Hard problems along with examples such as Subset Sum problem, Travelling Salesman Problem, optimization problem of finding the least cost cyclic route and much more.

Algorithms

Job Shop Problem

Job Shop Problem: We are given a number of jobs and machines. Each job constitutes a sequence of tasks which need to be performed in a particular order. Each task can be processed on a specific machine. We need to schedule all the tasks.

Algorithms

Find number of solutions of a linear equation of N variables

We have to find the number of solutions to a linear equation of N variables. We have solved this using Dynamic Programming.

Algorithms

Diameter of N-ary tree using Dynamic Programming

We are given input as the reference to the root of an N-ary tree. We need to calculate the diameter of the tree that is the longest path between any two nodes using Dynamic Programming.

Algorithms

Finding Diameter of Tree using Height of each Node

We have explored the algorithm on how to find the diameter of the tree using height of each node. This will take linear time O(V+E) time complexity.

Algorithms

Longest common substring using rolling hash approach

We can solve the longest common substring problem using the rolling hash technique in O(N * log(N)^2) time and O(N) space which is significantly better than other approaches.

Algorithms

Applications of Hash Map

HashMap in java.util package implements the Map interface in java collection based on Hashtable. There are three main applications of Hash Map: Priority Queues, Dijkstra's Algorithm and Topological Sort.

Algorithms

Find number of substrings with same first and last characters

You are given a string lets say "S" , you need to find the number of all contiguous substrings (part of "S") starting and ending with the same character.

Algorithms

Algorithms for Calculating Day of Week

Some of the Algorithms for Calculating Day of Week are: Tomohiko Sakamoto Algorithm, Gausses Algorithm and Wang's Algorithm. We have covered the basics of Julian and Georgian calender as well.

Algorithms

Wildcard Pattern Matching (Dynamic Programming)

In the Wildcard Pattern Matching problem, we find if a pattern matches a given input string. We will be using a Dynamic Programming approach with the time complexity of O(m * n), here m and n represent length of string and pattern respectively.

Software Engineering

SHA1 Algorithm (+ JavaScript Implementation)

In this article, we have explained the algorithmic steps in SHA1 Algorithm in depth. We have demonstrated an example by implementing SHA1 algorithm in JavaScript.

Algorithms

Finding Diameter of a Tree using DFS

In this article, we will be discussing how to find the diameter of a tree or graph using Depth First Search (DFS).

Algorithms

Diameter of a Binary Tree

In this problem, we are given input as the reference to the root of a binary tree. We need to find the diameter of the tree. We find the diameter using recursion and Depth First Search (DFS).

Algorithms

Understand Randomized Algorithms once and for all

In this post, we discuss what randomized algorithms are, and have a look at the Solovay-Strassen Primality Tester to see what they are like.

Algorithms

NP Complete Complexity

In this article, we have explored the idea of NP Complete Complexity intuitively along with problems like Clique problem, Travelling Salesman Problem and more.

Algorithms

Strategy to win Minesweeper

Many may think Minesweeper is a random game but it is a strategy game and you can win it everytime if you know the rules involved and proven strategies to play it.

Algorithms

C program to check whether brackets are Balanced in an Equation

We have developed a C program to check whether brackets are Balanced in an Equation using the Stack data structure and solving it in O(N) time.

Algorithms

Hospital Residents Problem

We have explored Hospital Residents Problem which is an matching problem similar to Stable Room Mates problem and Gale Shapley algorithm. In this, we match applicants to programs/ jobs.

Algorithms

Maximum cut problem

In this article we'll be discussing on the concept of Maximum cut problem. Firstly will understand its basic concept with Introduction. Secondly, with a graph example will deep-dive into the concept.

Algorithms

Find articulation point in Graph

In this article we'll be discussing on how to find articulation point in Graph. Firstly we'll discuss on the Introduction to Articulation Points. Secondly, we'll understand the Articulation Points concept with a graph example. At the end will write a Pseudo code & implementation for the same.

Algorithms

Number of substrings in a string divisible by 6

Given a string of integers, find the count of sub-strings of given string which are divisible by 6. This problem can be solved using Dynamic Programming in O(N) time complexity where N is the length of the string.

Algorithms

Algorithm to detect and remove loop in a Linked List

Given a Linked list, find out whether it contains a loop or not. If it does, then remove the loop and make the last node point to NULL.