并行计算PDD源代码，可用于求解三对角线性方程组，该算法是孙先河在上世纪提出的，因其具有良好的可扩展性而沿用至今-Parallel computing PDD source code can be used for solving tridiagonal linear equations, the algorithm is the first of its kind, Sun made in the last century, because of their good scalability