Answer:
The length of time on the road segment is calculated by taking it's distance and dividing by the speed at the time of departure. This length of time is then added to the departureTime parameter to get the arrivalTime.
Define a RiverSegment class that inherits from the base TransportationClass from above. This class will have a vector<double> scheduledDepartureTimes data field that will keep track of the departure time (e.g. 10.5 represents the time 10:30) of all ferries on the river. You can assume these are sorted. Additionally, there is a _speed value that is the speed of the ferry at all times (ferries tend to be consistently slow). There is a setSpeed function to change the _speed value. Additionally, there is an addDepartureTime(double hour) function to add a departure time to the vector. Make sure the time are sorted
Computing the arrival time for the RiverSegment is a little more complicated since you need to wait for the next available departure time. Once you find the next available departure time (after the departure time passed in), you need to add the length of time on the river segment. This is done by dividing the _distance by the _speed. Add the time on the river to the departure time (from the vector of departure times) and this will give you the arrive time.
note: If there is no departure time scheduled for after your planned departure, you need to take the first available departure the following day. Our solution assumes the departure times are the same every day.
TransportationLink.h
#include <string>
using namespace std;
#ifndef __TRANSPORTATIONLINK_H__
#define __TRANSPORTATIONLINK_H__
const int HOURS_PER_DAY = 24;
const int MINS_PER_HOUR = 60;
const int MINS_PER_DAY = MINS_PER_HOUR * HOURS_PER_DAY; //24 * 60
class TransportationLink {
protected:
string _name;
double _distance;
public:
TransportationLink(const string &, double);
const string & getName() const;
double getDistance() const;
void setDistance(double);
// Passes in the departure time (as minute) and returns arrival time (as minute)
// For example:
// 8 am will be passed in as 480 (8 * 60)
// 2:30 pm will be passed in as 870 (14.5 * 60)
virtual unsigned computeArrivalTime(unsigned minute) const = 0;
};
