//Dr. Ramsey - posted on March 7

#include <iostream>
using namespace std;


double compute_distance (double v, double a, double t);
void output(double v, double a, double t);

int main ()
{
  double acceleration=0.0, velocity=0.0, time=0.0;
  cout << "Input floating point velocity in ft/s: ";
  cin >> velocity;
  cout << "Input floating point acceleration in ft/(s*s): ";
  cin >> acceleration;
  cout << "Input floating point time in s: ";
  cin >> time;
  while (time < 0) //time must be >= 0
    {
      cout << "ERROR time is negative" << endl;
      cout << "Input positive time in s: ";
      cin >> time;
    }
  
  output(velocity, acceleration, time);
  
  
}

// a function to do output 
void output(double v, double a, double t)
{
  double s;
  s =  compute_distance(v,a,t);
  cout << "The distance is " << s << " feet."  << endl;
}

// a function to compute distance based on velocity acceleration and time
// time should not be negative when it reaches here, but it turns out
// this function does something reasonable if it is.
double compute_distance (double v, double a, double t)
{
  double s = 0.0;
  s = (v*t)  +  (0.5*a*t*t);
  return s;
}