I dont know what those two contests exactly means?
Does following format’s contest means a Long one?
“MonthNum”+“Challenge”+201X
And only does this “Challenge” contest contribute to the Long Contest’s Rating?
And also Short Contest
I don’t know what contest means short one and what will contribute to its rating.
Could u help me ?
Every month CodeChef hosts three kinds of contests these being the Long Contests(or Long Challenges), Short Contests (or Cook Offs) and newer Lunch Time Contests. Even though all three of these are official contests I am fairly certain that only the Long and Short contest have any rating associated with performance because Lunch Time contest are supposed to be an introduction to competitive programming for students.
To answer one of your questions since the Long Contest is the same as the Long Challenge yes it has the potential to contribute to a users Long Contest Rating.
As far as identification Long Contests typically last 10 days and normally consist of 10 questions of varying difficulty. They are easily identified by tags consisting of the month or an abbreviation of the month followed by the year (For example DEC13). Below is a link to the January Long Contest which demonstrates this.
The Short Contest typically last 2.5 hours and normally only consist of 5 questions of varying difficulty. These are also uniquely identified by a tag consisting of “COOK” and the number of the contest for example COOK01. Below is a link to the January Cook Off demonstrating this.
Just want to add a few things to what @felic92 has said:
1)Long contests are 10 day contests so the questions are generally slightly tougher than the short contests. As you have 10 days, you are expected to spend a lot of time on the problems and try to learn newer concepts. Also there are no limits on the number of times you attempt a question (except Challenge question which has a limit of 500 submissions !) and also no penalties for wrong attempts. So you have plenty of time to come up with a solution.
As a beginner it is very difficult to solve many problems in the short contests but you can definitely give them a try. Also keep learning new stuff through Long contests and by practicing in the practice Section and you will be a good coder in no time. Best of Luck!!