Odd terms of binomial coefficients
Given an integer n , find all binomial coefficients C(n,0)C_( n , 0 )C(n,0) , C(n,1)C_( n , 1 )C(n, 1) , … , how many items in C(n,n)C_( n , n )C(n,n) result in odd numbers.
An extension of Lucas' theorem
printf("%d\n",1<<__builtin_popcount(n));