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## Discussion of Problem 1091. Tmutarakan Exams

Sample example. What we must find?
Posted by IgorKoval(from Pskov) 11 Dec 2011 19:35
How get answer 11 for K==3 and S==10
I understand it so:

a b gcd(a,b)
2 4 2
2 6 2
2 8 2
2 10 2
3 6 3
3 9 3
4 2 2
4 6 2
4 8 4
4 10 2
5 10 5
6 2 2
6 3 3
6 4 2
6 8 2
6 9 3
6 10 2
8 2 2
8 4 4
8 6 2
8 10 2
9 3 3
9 6 3
10 2 2
10 4 2
10 5 5
10 6 2
10 8 2
So, cnt = 28 //count of pair a, b

And my answer is 28. Why am wrong? And how use 'K'? =)

Edited by author 11.12.2011 19:36
Re: Sample example. What we must find?
Posted by Artyom Averin{USU} 13 Dec 2011 17:26
"You should find the number of sets of K different numbers"
sets of K different numbers
Re: Sample example. What we must find?
Posted by IgorKoval(from Pskov) 13 Dec 2011 21:04
Please, give some example of "sets of K different numbers"( there are 11 sets(from Sample example) ) for K==3 and S==10.
Thank you.

Edited by author 13.12.2011 21:07

Edited by author 13.12.2011 21:07
Re: Sample example. What we must find?
Posted by IgorKoval(from Pskov) 13 Dec 2011 21:28
a b  c fgcd(c,fgcd(a,b))
2 4  6 2
2 4  8 2
2 4 10 2
2 6  8 2
2 6 10 2
2 8 10 2
3 6  9 3
4 6  8 2
4 6 10 2
4 8 10 2
6 8 10 2
cnt = 11

fgcd - function which return greatest common divisor

Edited by Trolol 13.12.2011 21:30

Edited by author 13.12.2011 21:50