During winter vacation at IIIT Hyderabad, around December 2013, I was addicted to solving competitive programming questions on sites like Codechef, Spoj, etc. These questions challenged me intellectually and made me think hard and build skills to translate real world entities and conditions into code.
During that winter vacation, I solved 463 questions in total and was pushing the solutions to a Github repository. As I realize there are lots of students and programming enthusiasts who look for optimal and working solutions to understand the approach better, I am putting all of my solutions here.
I encourage you to first try to code the solution by yourself, struggle for at least an hour or two and then if you do not get it right, look for the solution here. Happy Coding!