说明：  The Reed-Somolon code is specified by the finite field, the length (length <= 2^m-1), the number of redundant symbols (length-k), and the initial zero of the code, init_zero, such that the zeros are: init_zero, init_zero+1, ..., init_zero+length-k-1
(The Reed-Somolon code is specified by the f inite field, the length (length)