The month of April held a special significance in the programming world, with the ACM-ICPC World Finals crowning a new world champion. So how about you cap off this brilliant month with Chef’s next contest, the April Lunchtime 2018 and join your fellow programmers and enjoy the contest problems.

Joining me on the problem setting panel are:

Problem Setters, Editorialists and Russian Translators: gainullinildar (Ildar Gainullin), altruist_ (Denis Anischenko)

Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, are requested to register in order to participate.

Prizes:
Top 10 performers in Global and Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: "Laddus" For You | CodeChef. (For those who have not yet got their previous winning, please send an email to winners@codechef.com)

Good Luck!
Hope to see you participating!!
Happy Programming!!

For me, understanding Triple Tree Decomposition proved really difficult. IDK, the meaning just didnt strike me- to that extent, that I dont know WHY I got 80 points. I could just vaguely get that setter wants us to check if each node has 3*k edges to divide into sets…? Can anyone elaborate?

This is one of the question where explanation of sample Input Output would be a great convenience. If its not really necessary, please dont skip that section.

EDIT- Also please explain what should be the output for cases when N\le 3. I was assuming that its “Yes” because of vacuous truth, but solutions printing “No” for these are accepted.

I have no karma points and I want to ask a question that Question is related to April Lunchtime 2018 The problem code is GCDDIV I found two submissions which got 100 points One is CodeChef: Practical coding for everyone and the second is CodeChef: Practical coding for everyone The first submission got 100 points event thought It does not deserve 100 points because that fails for the test cases like

1
3 6
101 10201 1030301

For this the solution 18380850 gives its answer as “YES” but the right answer is “NO” solution 18375921 gives correct answer as “NO” for the above test case

Returns ‘YES’ for some submissions and ‘NO’ for other but both are marked as correct by the judge.

From my point of view, ‘YES’ will be correct answer as gcd of above number will be 18 which can be represented as 2*9 (both 9 and 2 being less than 10).
Link to both solution are:

3rd problem was quite confusing, so i started doing it on paper. Since it was written that we’re required to print (N-1)/3 lines of output for each testcase, and later i found out why is it so.
So, for 1st subtask, i.e. N<=10 answer is YES for N=4,7,10 and that is also in some cases. I figured that out and wrote code for these special cases to get Partial Score. I know this is not how we should deal with the questions, but just for the sake of my curiosity, i am asking this here.
However, I found out that for 1st subtask the input value of N in TestFile is just 10.
If anyone of you have some time, plz give my solution a glance, i don’t know why i got WA.

If you draw this one, you can find that the special thing here is that node 4 is shared. Anyone terminating search at node 4 (on getting condition like number of edges from this node is not a multiple of 3) will suffer a WA here. Didnt check your solution, but I will say try for yourself once for smaller cases.

The goal was to make the GCD of the array 1, to do that, just find the GCD of the array and divide it with each element and thats it,but now if the GCD is greater than K you can’t divide it directly so divide with the prime factors of GCD, if its not possible then its “NO”.