  At present, only some special differential equations have explicit analytical
solutions. In general, no one thinks that it is possible to analytically find
the exact solution of nonlinear equations. In this article based on the idea
that the numerical scheme with zero truncation error can give rise to exact
solution, a general formula for the exact solution of the initial value problem
of nonlinear ordinary differential equations is obtained. Meanwhile, this
formula enables us to construct a numerical scheme with zero truncation error
for solving the nonlinear differential equations.
