# include <cstdlib>
# include <iostream>

using namespace std;

double euler ( double t0, double u0, double dt, 
  double f ( double t, double u ) );
double f2 ( double t, double u );

int main ( )
{
  double dt, t0, t1, tmax, u0, u1;

  u0 = 2;
  t0 = 1850;
  tmax = 2000;
  
  dt = 1.0;
  
  cout << "\n";
  cout << "    T     U(T)\n";
  cout << "\n";
  
  while ( true )
  {
    cout << "  " << t0 << "  " << u0 << "\n";
    if ( tmax <= t0 )
    {
      break;
    }
    t1 = t0 + dt;
    u1 = euler ( t0, u0, dt, f2 );

    t0 = t1;
    u0 = u1;
  }
  
  return 0;
}
double euler ( double t0, double u0, double dt, double f ( double t, double u ) )
{
  double u1;
  
  u1 = u0 + dt * f ( t0, u0 );
  
  return u1;
}
double f2 ( double t, double u )
{
  double dudt, umax = 750.0, c = 0.10;
  
  dudt = c * u * ( 1.0 - u / umax );
  
  return dudt;
}