If n+1 integers a0,a1,a2.....an are given then how can we find efficiently the value of
nC0*a0 -nC1*a1 + nC2*a2 -nC3*a3 + ..... +/- nCn*an (mod 1000000007)
Actually this is the problem of hackerrank.com's SprintIndia qualification round.
n<=10^5 and time limit is 2 sec.
Thanks in advance.. :)