Reversing words in a string is a popular coding interview question. Here what is meant by reversing words in a string is something like this. Input string: "My name is rajind and i am a believer" Output string: "believer a am i and rajind is name My" Doing this in-place without use additional space … Continue reading Reverse Words in a String
Author: Rajind Ruparathna
A software engineer, blogger and a tech enthusiast!
Block Art – IEEEXtreme 9.0
Problem Statement The NeoCubist artistic movement has a very distinctive approach to art. It starts with a rectangle which is divided into a number of squares. Then multiple rounds of layering and scraping occur. In a layering round, a rectangular region of this canvas is selected and a layer of cubes, 1 cube deep, is … Continue reading Block Art – IEEEXtreme 9.0
Digit Fun! – IEEEXtreme 9.0
Problem Statement Recurrence relations are an important tool for the computer scientist. Many algorithms, particularly those that use divide and conquer, have time complexities best modeled by recurrence relations. A recurrence relation allows us to recursively define a sequence of values by defining the nth value in terms of certain of its predecessors. Many natural … Continue reading Digit Fun! – IEEEXtreme 9.0
WiFi Information Extraction Java
Hello everyone, I was recently involved in a wireless networking project where we had to develop a student response system. In that I had to extract certain WiFi related information such as list of available SSIDs, connected SSID, IP address and Subnet Mask Java doesn't allows us to directly get that low level information. Therefore … Continue reading WiFi Information Extraction Java
Introduction to Algorithms (CLRS) Solutions Collection
This is a collection of solutions which I put together from various University course websites for the Introduction to Algorithms CLRS. It is not in any order but you could search for the question number and find what you want. Hope this might be useful to you all as it was helpful for me. Cheers! … Continue reading Introduction to Algorithms (CLRS) Solutions Collection
Cookie Clicker Alpha – Problem B – Google Code Jam 2014 Qualification Round
Introduction (Link to Question Page in Code Jam Website) Cookie Clicker is a Javascript game by Orteil, where players click on a picture of a giant cookie. Clicking on the giant cookie gives them cookies. They can spend those cookies to buy buildings. Those buildings help them get even more cookies. Like this problem, the … Continue reading Cookie Clicker Alpha – Problem B – Google Code Jam 2014 Qualification Round
Magic Trick – Problem A – Google Code Jam 2014 Qualification Round
Problem (Link to Question Page in Code Jam Website) Recently you went to a magic show. You were very impressed by one of the tricks, so you decided to try to figure out the secret behind it! The magician starts by arranging 16 cards in a square grid: 4 rows of cards, with 4 cards … Continue reading Magic Trick – Problem A – Google Code Jam 2014 Qualification Round
Linked List with Read-Write Locks for the Entire Linked List
Implementation of a linked list as a Parallel program (based on Pthreads) with read-write locks for the entire linked list https://github.com/Rajind/LinkedLists-in-C Parallel program (based on Pthreads) with read-write locks for the entire linked list How to compile and run the program: *linked_list_one_rwlock.c gcc -g -Wall -o linked_list_one_rwlock linked_list_one_rwlock.c -lpthread ./linked_list_one_rwlock parameter_1 --------------------------------------------------- parameter_1 : is … Continue reading Linked List with Read-Write Locks for the Entire Linked List
Linked List with One Mutex for the Entire Linked List
Implementation of a linked list as a Parallel program (based on Pthreads) with one mutex for the entire linked list https://github.com/Rajind/LinkedLists-in-C Parallel program (based on Pthreads) with one mutex for the entire linked list How to compile and run the program: *linked_list_one_mutex.c gcc -g -Wall -o linked_list_one_mutex linked_list_one_mutex.c -lpthread ./linked_list_one_mutex parameter_1 --------------------------------------------------- parameter_1 : is the … Continue reading Linked List with One Mutex for the Entire Linked List
Solution to Senate Bus Problem
This is Java Implementation of the Semaphore based solution for Senate Bus Problem https://github.com/Rajind/SenateBusProblem The Senate Bus Problem (From The Little Book of Semaphores by Allen B. Downey) This problem was originally based on the Senate bus at Wellesley College. Riders come to a bus stop and wait for a bus. When the bus arrives, all … Continue reading Solution to Senate Bus Problem
Notebook 