please provide me an efficient answer.
Most of the tech giants know that beginners ( mere graduates ) have very little or no industrial exposure. They don’t expect us to building good products. You have ample to time to do that once you are recruited. However, they want you to be firm in data structures and algorithms. They basically test your problem solving skills and aptitude. Codechef helps you in this by providing ample of practice problems . It provides a platform to compete with the best coders of the world and learn from them. You also find others’ approaches to the same problem which helps you to increase your level.
Also Codechef has a lot to offer once you are consistent in coding. 