求解一维的微分方程，其中涉及到三对角矩阵的特殊的LU分解，基于fft思想的求解（但是并没应用fft），以及共对两个微分方程进行了求解。-Solving differential equations of one-dimensional, which involves tridiagonal matrix special LU decomposition, based on the the fft thinking of solving (but no application fft), as w