Interpolation of dense and sparse rational functions and other improvements in FireFly

We present the main improvements and new features in version 2.0 of the open-source C++ library FireFly for the interpolation of rational functions. This includes algorithmic improvements, e.g. a hybrid algorithm for dense and sparse rational functions and an algorithm to identify and remove univariate factors. The new version is applied to a Feynman-integral reduction to showcase the runtime improvements achieved. Moreover, FireFly now supports parallelization with MPI and offers new tools like a parser for expressions or an executable for the insertion of replacement tables.本文介绍了用于有理函数插值的开源C++库FireFly 2.0版本的主要改进与新增功能。其中涵盖算法层面的优化，例如面向稠密与稀疏有理函数的混合算法，以及用于识别并移除单变量因子的算法。新版本通过应用于费曼积分约化场景，展示了其在运行性能上的提升效果。此外，FireFly现已支持基于MPI（Message Passing Interface）的并行计算，并新增了表达式解析器、替换表插入可执行程序等工具。