#include <stdio.h>
#include <iostream.h>
#include <math.h>
//all the include statements are like toolboxes of commands and capabilities
//  without them, you couldn't do math or anything requiring input or output!
//note:name of file usually must have proper extension, depending on
//compiler, e.g. .cpp for microsoft C++.
int main()
{
     FILE *fp;
     fp=fopen("fudge","w");
double dt,v,t;
double z;
double vo;
// notice that all variables are declared double precision at the start.
//  File and fp statements open a file named fudge for data storage
//  Next initialize z.
z=0.;


cout<<"enter vo"<<endl;
cin >>vo;
cout<<"enter dt"<<endl;
cin >>dt;
t=t-dt;
do {
     t=t+dt;
z=z+v*dt;
v=vo-9.8*dt;
vo=v;
fp=fopen("fudge","a");
fprintf(fp,"%18.6f%18.6f\n",t,z);


fclose(fp);
//results are in fudge and also outputted to the screen.
cout <<"t="<<t<<"  z="<<z<<endl;
} while (t<15);
// obviously, making the upper limit larger in the previous statment will
//run the code longer.
return 0;
}