Файлы 2

#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
using namespace std;

int main()
{
    float g=9.81;
    ifstream infile("/home/user/in.txt");
    string line;
    getline(infile,line);
    istringstream iny(line.c_str());
    float x ,y, vx, vy, dt;
    iny>>x>>y>>vx>>vy>>dt;
    infile.close();
    ofstream outfile;
    float eps = 0.001;
    outfile.open("/home/user/out.txt");
    while (vx * vx + vy * vy > eps){
        x=x+vx*dt;
        y=y+vy*dt;
        outfile << x << "    " << y << endl;
        vy-=g*dt;
        cout << x << "\t" << y << "\t" << vx << "\t" << vy << endl;
        if (y<0){
            y=0;
            vy*=-0.5;
            vx*= 0.5;


        }

        outfile<<x<<' '<<y<<endl;

    }

    outfile.close();
    return 0;
}