main.cpp

ssd5 exam2 答案

#pragma warning(disable:4786)

#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <stack>
#include <stdexcept>
#include <vector>
#include <algorithm>

#include "car.h"

using namespace std;

const int PARKING_SPOTS_PER_AISLE = 3;
const int NUMBER_OF_AISLES = 5;

void handle_arrival(vector<Car>&, vector<stack<string> >&, const string&);
void handle_departure(vector<Car>&, vector<stack<string> >&, const string&);
Car& find_car(vector<Car>&, string);

int main(int argc, char* argv[]) {

    try {

        if (argc != 2) {
            cerr << "Usage:\n" << argv[0] << " data-file";
            return EXIT_FAILURE;
        }    

        ifstream inf(argv[1]);
        if (! inf) {
            cerr << "Could not open " << argv[1];
            return EXIT_FAILURE;
        }

		vector<Car> cars;
		vector< stack<string> > parking_lot(NUMBER_OF_AISLES);

        while (! inf.eof()) {
        
            string action, plate;
            inf >> plate >> action;
        
            if (action == "arrives") {
                handle_arrival(cars, parking_lot, plate);
            } 
            else if (action == "departs") {
                handle_departure(cars, parking_lot, plate);            
            } else {
                cerr << "Unknown action: " << action << endl;
            }
        
        }
        inf.close();    

        cout << "\nHere are all the cars that visited the lot today:\n";

        // TODO: Output the license plates of all the
        // cars that visited the lot, in alphabetical order		
		std::sort(cars.begin(), cars.end());               //use STL algorithm sort() to sort the vector of cars
		for (vector<Car>::iterator itr_car = cars.begin(); itr_car !=  cars.end(); itr_car++) {            //displays an alphabetized list of all the cars that visited the parking lot during the simulation
			cout << (*itr_car).getPlate() << endl;
		}
        return EXIT_SUCCESS;
        
    }
    catch (exception& e) {
        cerr << e.what() << endl;
    }
    catch (...) {
        cerr << "Unknown exception caught!" << endl;
    }
    
    return EXIT_FAILURE;
}


/*
 * This function should iterate through the vector of stacks, looking for
 * the first stack that does not contain three cars. If all five aisles 
 * (stacks) are full, output a message indicating such; otherwise place 
 * the license plate into the first non-full stack. 
 */
void handle_arrival(vector<Car>& cars, vector< stack<string> >& parking_lot, const string& plate) {

    for (int i = 0; i < NUMBER_OF_AISLES; i++) {              //cycle to find the first empty place 
		if (parking_lot[i].size() < PARKING_SPOTS_PER_AISLE) {//if it is not full
			parking_lot[i].push(plate);                       //push the lience of the car into this aisle
			cars.push_back(Car(plate, i));                    //add an entry of type Car to the vector cars
			return;
		}
		if (i == NUMBER_OF_AISLES - 1) {                      //if all the aisles are full
			cout << "Sorry! parking_lot is full" << endl;     //output such information
		}
	}
}

/*
 * This function should locate the departing vehicle from the cars vector
 * using function find_car. Then this function should remove the departing
 * car's license plate from the appropriate aisle.
 */
void handle_departure(vector<Car>& cars, vector< stack<string> >& parking_lot, const string& plate) {

    Car & car = find_car(cars, plate);                      //find the car which wants to leave
	int i = car.getAisle();                                 //get the car's aisle 
	stack<string> temStack;                                 //creat a temporary stack to hold cars in front of it
	while (parking_lot[i].top() != plate) {                 //if the top lience is not the specific car's  
		string str_moved = parking_lot[i].top();            //get it's lience to push into temporary stack latter
		Car & car_moved = find_car(cars, str_moved);        //get the car to be moved
		car_moved.setTimesMoved(car_moved.getTimesMoved() + 1);//increase this car's moved times
		temStack.push(str_moved);                              //move the car into temporary stack
		parking_lot[i].pop();                                  //delete it in the aisle
	}
	cout << plate << " was moved " << find_car(cars, plate).getTimesMoved() << " times while it was here" << endl;//display the car's moving information before it leaves  
	parking_lot[i].pop();                                      //delete it in the aisle  
	while (!temStack.empty()) {                                //if the temporary is not empty
		parking_lot[i].push(temStack.top());                   //move it back to aisle
		temStack.pop();                                        //delete it in the temporary stack
	}
}

/*
 * This function returns a reference to the Car object stored in the vector 
 * cars whose license plate equals the parameter plate.
 */
Car& find_car(vector<Car>& cars, string plate) {

	// TODO: Return a reference to the 
	// the Car object whose license plate equals 
	// the parameter 'plate'
	vector<Car>::iterator itr = std::find(cars.begin(), cars.end(), Car(plate)); //get the specific car through invoking STL find()
	return *itr;                                                                 //return it
}