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321 ira 1 
 
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#include "controller.h"
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Controller::Controller (int num_floors, int num_elevators) : num_floors (num_floors), num_elevators (num_elevators)
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{
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    assert (num_floors > 2);
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    assert (num_elevators > 0);
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    elevators = std::vector<Elevator> (num_elevators, Elevator (num_floors));
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}
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Controller::~Controller ()
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{
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}
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void Controller::request_elevator (int on_floor)
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{
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    assert (on_floor <= num_floors);
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    assert (on_floor > 0);
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    float distance = INT_MAX;
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    int elevator_number;
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    // check that there is not already an elevator requested
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    // to this floor. If there is already one, ignore this
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    // request.
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    if (floor_already_requested (on_floor))
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        return;
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    // find elevator that is closest, AND NOT moving away
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    // "push" it's button
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    elevator_number = find_closest_elevator (on_floor);
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    elevators[elevator_number].push_button (on_floor);
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}
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/**
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 * Check if there is an elevator already in the queue to stop
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 * at the floor given as a parameter.
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 */
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bool Controller::floor_already_requested (int on_floor)
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{
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    int i;
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    for (i=0; i<num_elevators; i++)
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        if (elevators[i].button_is_pushed (on_floor))
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            return true;
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    return false;
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}
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/**
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 * Return the number of the closest elevator to the
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 * floor given as a parameter.
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 *
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 * We only want to choose elevators that are close and
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 * heading in the right direction, or the closest elevator
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 * if it is sitting idle.
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 */
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int Controller::find_closest_elevator (int to_floor)
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{
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    int i;
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    float distance = INT_MAX;
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    float temp_distance;
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    int answer;
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    float cur_floor;
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    int direction;
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    for (i=0; i<num_elevators; i++)
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    {
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        cur_floor = elevators[i].get_current_floor ();
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        direction = elevators[i].get_direction ();
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        temp_distance = fabsf (cur_floor - to_floor);
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        // Check that this elevator is closer
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        if (temp_distance < distance)
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        {
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            // If we are below the floor we want to go to and we
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            // are moving up, then this is an ok choice
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            if (cur_floor < to_floor && direction == MOVE_UP)
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            {
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                answer = i;
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                distance = temp_distance;
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            }
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            // If we are above the floor we want to go to and we
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            // are moving down, then this is an ok choice
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            else if (cur_floor > to_floor && direction == MOVE_DOWN)
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            {
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                answer = i;
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                distance = temp_distance;
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            }
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            // If we are closest, but idle, then this is an ok choice
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            else
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            {
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                answer = i;
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                distance = temp_distance;
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            }
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        }
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    }
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    return answer;
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}
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