Help regarding CSEQ [April Challenge]?

help
,
1

I was not able to solve this problem during contest, but this is my CSEQ code
-> http://ideone.com/iaqmIp

codechef solution link -> http://www.codechef.com/viewsolution/6781060

I cant figure out why there is error in program.

Can anyone please help me, as, this is not getting accepted now ?

Thanks.

2

you are calculating wrong Combinatorial(n,r) you had to calculate combinatorial( (r-l+1),(n+ r-l+1))-1.