说明：  把微分方程的一维经典初值问题的有限插分法：Euler法、改进的Euler法、Admas二步外插法、Admas二步内插法编写成通用子程序，并且利用这些通用子程序解决常微分方程的数值解。
(The one-dimensional finite-drop method of differential equations of classical initial value problem: write Euler method, Improved Euler method, Admas two-step extrapolation, Admas the two-step interpolation into a common subroutines, and the use of these generic routines to solve numerical solution of ordinary differential equations.)