Python 3 version of the original spinal codes.
C99 version of the spinal codes. (Or any other C version that supports VLA).
k,B,d are parameters that influenced the time consumption drastcially. When k,B,d are too large, the decoding complexity is too enough to be used in practical. So in this C version, I choose k=4, B=4, d=2 which is as same as the original python version.