该段代码实现了Robust Soliton distribution，这个分布是LT编码的核心环节，他将产生LT编码所需的度，从而使得LT编码能够达到预期的性能。-The section of code to achieve the Robust Soliton distribution, this distribution is a core part of LT codes, he will have the necessary degree of LT codes, allowing LT