@jit(nopython=True, cache=True)
def next_k_combination(x):
 u = (x & (- x))
 v = (u + x)
 return (v + (((v ^ x) // u) >> 2))

@ jit ( nopython = True , cache = True ) def next_k_combination ( x ) : u = ( x & ( - x ) ) v = ( u + x ) return ( v + ( ( ( v ^ x ) // u ) >> 2 ) )
find the next k-combination .