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Practice Coding Interview Problems

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Coin Change: Find number of ways of representing n cents

Dynamic Programming

Designing a scalable URL Shortener like Tiny URL

System Design - Nlogn

Reverse a linked list in Linear Time without using extra space

Linked List

Insert, Search and Delete Operation in Binary Search Tree

Tree Data Structure

Latest blog post at Nlogn

Count the number of islands

Given a binary 2D matrix, containing the combination of 1's and 0's, where 0's represents the water and 1's represent the land. Our...

Call by value and call by reference in C++

There are two ways to pass arguments to a function in CPP: Call by Value or Call by Reference. The Call by Value...

What are Long Polling, WebSockets, and Server-Sent Events

Before understanding Long Polling, WebSockets, Server-Sent Events lets understand how the basic communication over the internet using HTTP request happens. HTTP is the...

Designing Instagram Architecture – System Design

The prerequisite for learning the Instagram architecture design is, how to design a URL Shortner Service like a tiny URL. Please read it...

Count all possible paths between two vertices of a directed graph

Given a directed graph G, and two vertices: start s & end e, count all possible way of reaching the vertex e from...

Minimum number of swaps required to sort a given array

Problem Statement: Given an array of n distinct elements, we have to find the minimum number of swaps required to sort the given...