基本上，我正在做一些课程，要求我创建一个允许最多两站的航班预订系统，例如伦敦到巴黎到巴塞罗那到汉堡。我设法创建一个版本，其中1停止工作，例如伦敦到巴黎到巴塞罗那，但我不能让这个工作。我已经在下面包含了我的代码，每当我调用此函数并将其传递给任何两个机场时，它都不输出任何内容。我很欣赏下面的代码是冗长的，但很多都是重复的。我也可能以完全错误的方式编写这个问题。如果您对如何处理此问题有任何更好的想法，请分享。
非常感谢。
void searchAllFlights(string origin, string destination)
{
ifstream checkNumOfLines("flights.txt");
int numOfLines = 0;
for(string line; getline(checkNumOfLines, line);){
numOfLines++;
}
int lengthOfLines[10] = {0,0,0,0,0,0,0,0,0,0};
checkNumOfLines.clear();
checkNumOfLines.seekg(0, ios::beg);
int index = 0;
for(string line; getline(checkNumOfLines, line);){
lengthOfLines[index] = line.length();
index++;
}
int filePointers[11] = {0, lengthOfLines[0], lengthOfLines[0] + lengthOfLines[1], lengthOfLines[0] + lengthOfLines[1] + lengthOfLines[2],
lengthOfLines[0] + lengthOfLines[1] + lengthOfLines[2] + lengthOfLines[3], lengthOfLines[0] + lengthOfLines[1] + lengthOfLines[2] +
lengthOfLines[3] + lengthOfLines[4], lengthOfLines[0] + lengthOfLines[1] + lengthOfLines[2] +
lengthOfLines[3] + lengthOfLines[4] + lengthOfLines[5], lengthOfLines[0] + lengthOfLines[1] + lengthOfLines[2] +
lengthOfLines[3] + lengthOfLines[4] + lengthOfLines[5] + lengthOfLines[6], lengthOfLines[0] + lengthOfLines[1] + lengthOfLines[2] +
lengthOfLines[3] + lengthOfLines[4] + lengthOfLines[5] + lengthOfLines[6] + lengthOfLines[7], lengthOfLines[0] + lengthOfLines[1]
+ lengthOfLines[2] + lengthOfLines[3] + lengthOfLines[4] + lengthOfLines[5] + lengthOfLines[6] + lengthOfLines[7] + lengthOfLines[8],
lengthOfLines[0] + lengthOfLines[1] + lengthOfLines[2] + lengthOfLines[3] + lengthOfLines[4] + lengthOfLines[5] + lengthOfLines[6] +
lengthOfLines[7] + lengthOfLines[8] + lengthOfLines[9]};
ifstream flights("flights.txt");
startingDeparturePoint = origin;
endDestinationPoint = destination;
totalFlightsPrice = 0;
totalFlightDuration = 0;
string originFromFile;
string destFromFile;
string airline;
int price;;
int flightDuration;
cout << "No. |" << "Origin |" << "Destination |" << "Airline |" << "Price |" << "Duration |" << endl;
cout << "----------------------------------------------------------------------------------------" << endl;
matches = 0;
int currentLine = 0;
while(flights >> originFromFile >> destFromFile >> airline >> price >> flightDuration)
{
//flights.seekg(setfilepos, ios::beg);
int numberOfChars = originFromFile.length() + destFromFile.length() + airline.length();
if(originFromFile == startingDeparturePoint && destFromFile == endDestinationPoint)
{
matches++;
directFlight(originFromFile, destFromFile, airline, price, flightDuration);
}
else if(originFromFile != startingDeparturePoint && destFromFile == endDestinationPoint)
{
matches++;
string stopoverLast = originFromFile;
string airlineLast = airline;
int priceLast = price;
int flightDurationLast = flightDuration;
int currentIndex = firstOrigins.size() + 1;
secondOrigins[currentIndex] = stopoverLast;
secondDests[currentIndex] = destFromFile;
secondAirlines[currentIndex] = airlineLast;
secondPrices[currentIndex] = priceLast;
secondFlightDurations[currentIndex] = flightDurationLast;
ifstream flights2("flights.txt");
string originFromFile2;
string destFromFile2;
string airlineFromFile2;
int priceFromFile2;
int flightDurationFromFile2;
while(flights2 >> originFromFile2 >> destFromFile2 >> airlineFromFile2 >> priceFromFile2 >> flightDurationFromFile2){//1q
if(destFromFile2 == stopoverLast){
firstOrigins.push_back(originFromFile2);
firstDests.push_back(destFromFile2);
firstAirlines.push_back(airlineFromFile2);
firstPrices.push_back(priceFromFile2);
firstFlightDurations.push_back(flightDurationFromFile2);
if(originFromFile2 != startingDeparturePoint){
thirdOrigins[currentIndex] = secondOrigins[currentIndex];
thirdDests[currentIndex] = secondOrigins[currentIndex];
thirdAirlines[currentIndex] = secondOrigins[currentIndex];
thirdPrices[currentIndex] = secondPrices[currentIndex];
thirdFlightDurations[currentIndex] = secondFlightDurations[currentIndex];
secondOrigins[currentIndex] = firstOrigins[currentIndex];
secondDests[currentIndex] = firstOrigins[currentIndex];
secondAirlines[currentIndex] = firstOrigins[currentIndex];
secondPrices[currentIndex] = firstPrices[currentIndex];
secondFlightDurations[currentIndex] = firstFlightDurations[currentIndex];
ifstream flights3("flights.txt");
string originFromFile3;
string destFromFile3;
string airlineFromFile3;
int priceFromFile3;
int flightDurationFromFile3;
while(flights3 >> originFromFile3 >> destFromFile3 >> airlineFromFile3 >> priceFromFile3 >> flightDurationFromFile3){
if(originFromFile3 == startingDeparturePoint && destFromFile3 == secondOrigins[currentIndex]){
firstOrigins[currentIndex] = originFromFile3;
firstDests[currentIndex] = destFromFile3;
firstAirlines[currentIndex] = airlineFromFile3;
firstPrices[currentIndex] = priceFromFile3;
firstFlightDurations[currentIndex] = flightDurationFromFile3;
while(flights3 >> originFromFile3 >> destFromFile3 >> airlineFromFile3 >> priceFromFile3 >> flightDurationFromFile3){
if(originFromFile3 == startingDeparturePoint && destFromFile3 == secondOrigins[currentIndex]){
firstOrigins.push_back(firstOrigins[currentIndex]);
firstDests.push_back(firstDests[currentIndex]);
firstAirlines.push_back(firstAirlines[currentIndex]);
firstPrices.push_back(firstPrices[currentIndex]);
firstFlightDurations.push_back(firstFlightDurations[currentIndex]);
secondOrigins[currentIndex + 1] = secondOrigins[currentIndex];
secondDests[currentIndex + 1] = secondDests[currentIndex];
secondAirlines[currentIndex + 1] = secondAirlines[currentIndex];
secondPrices[currentIndex + 1] = secondPrices[currentIndex];
secondFlightDurations[currentIndex + 1] = secondFlightDurations[currentIndex];
thirdOrigins[currentIndex + 1] = originFromFile3;
thirdDests[currentIndex + 1] = destFromFile3;
thirdAirlines[currentIndex + 1] = airlineFromFile3;
thirdPrices[currentIndex + 1] = priceFromFile3;
thirdFlightDurations[currentIndex + 1] = flightDurationFromFile3;
}
}
}
}
}
else{
currentIndex++;
while(flights >> originFromFile >> destFromFile >> airline >> price >> flightDuration){
if(originFromFile != startingDeparturePoint && destFromFile == endDestinationPoint){
matches++;
stopoverLast = originFromFile;
airlineLast = airline;
priceLast = price;
flightDurationLast = flightDuration;
secondOrigins[currentIndex] = stopoverLast;
secondDests[currentIndex] = destFromFile;
secondAirlines[currentIndex] = airlineLast;
secondPrices[currentIndex] = priceLast;
secondFlightDurations[currentIndex] = flightDurationLast;
firstOrigins.push_back(originFromFile2);
firstDests.push_back(destFromFile2);
firstAirlines.push_back(airlineFromFile2);
firstPrices.push_back(priceFromFile2);
firstFlightDurations.push_back(flightDurationFromFile2);
while(flights2 >> originFromFile2 >> destFromFile2 >> airlineFromFile2 >> priceFromFile2 >> flightDurationFromFile2){
currentIndex++;
secondOrigins[currentIndex] = stopoverLast;
secondDests[currentIndex] = destFromFile;
secondAirlines[currentIndex] = airlineLast;
secondPrices[currentIndex] = priceLast;
secondFlightDurations[currentIndex] = flightDurationLast;
firstOrigins.push_back(originFromFile2);
firstDests.push_back(destFromFile2);
firstAirlines.push_back(airlineFromFile2);
firstPrices.push_back(priceFromFile2);
firstFlightDurations.push_back(flightDurationFromFile2);
}
}
}
}
}
}
}
break;
}
// loop over vectors and print out results, put in conditional statements to
//check if 2nd and 3rd flights exist, if they do add the "-----" after
for(int i = 0; i < firstOrigins.size(); i++){
int mins = firstFlightDurations[i];
int hours = 0;
while(mins >= 60){
hours++;
mins -= 60;
}
cout << "No. |" << "Origin |" << "Destination |" << "Airline |" << "Price |"
<< "Duration " << endl;
if(firstOrigins[i] != "-"){
cout << left << setw(4) << setfill(' ') << 1 << right << "|";
cout << left << setw(7) << setfill(' ') << firstOrigins[i] << right << "|";
cout << left << setw(12) << setfill(' ') << firstDests[i] << right << "|";
cout << left << setw(20) << setfill(' ') << firstAirlines[i] << right << "|";
cout << left << "\x9c" << setw(13) << setfill(' ') << left << firstPrices[i] << right << "|";
cout << left << hours << "hr(s) " << mins << "min(s)" << setw(11) << setfill(' ') << right << "|" << endl;
if(secondOrigins[i] != "-"){
int mins2 = secondFlightDurations[i];
int hours2 = 0;
while(mins2 >= 60){
hours2++;
mins2 -= 60;
}
totalFlightsPrice = firstPrices[i] + secondPrices[i];
totalFlightDuration = firstFlightDurations[i] + secondFlightDurations[i] + thirdFlightDurations[i];
cout << left << setw(4) << setfill(' ') << 1 << right << "|";
cout << left << setw(7) << setfill(' ') << secondOrigins[i] << right << "|";
cout << left << setw(12) << setfill(' ') << secondDests[i] << right << "|";
cout << left << setw(20) << setfill(' ') << secondAirlines[i] << right << "|";
cout << left << "\x9c" << setw(13) << setfill(' ') << left << secondPrices[i] << right << "|";
cout << left << hours2 << "hr(s) " << mins2 << "min(s)" << setw(11) << setfill(' ') << right << "|" << endl;
if(thirdOrigins[i] != "-"){
int mins3 = secondFlightDurations[i];
int hours3 = 0;
while(mins3 >= 60){
hours3++;
mins3 -= 60;
}
totalFlightsPrice = firstPrices[i] + secondPrices[i] + thirdPrices[i];
totalFlightDuration = firstFlightDurations[i] + secondFlightDurations[i] + thirdFlightDurations[i];
cout << left << setw(4) << setfill(' ') << 1 << right << "|";
cout << left << setw(7) << setfill(' ') << thirdOrigins[i] << right << "|";
cout << left << setw(12) << setfill(' ') << thirdDests[i] << right << "|";
cout << left << setw(20) << setfill(' ') << thirdAirlines[i] << right << "|";
cout << left << "\x9c" << setw(13) << setfill(' ') << left << thirdPrices[i] << right << "|";
cout << left << hours3 << "hr(s) " << mins3 << "min(s)" << setw(11) << setfill(' ') << right << "|" << endl;
int totalmins = totalFlightsPrice;
int totalhours = 0;
while(totalmins >= 60){
totalhours++;
totalmins -= 60;
}
cout << left << setw(4) << setfill(' ') << " " << right << "|";
cout << left << setw(7) << setfill(' ') << " " << right << "|";
cout << left << setw(12) << setfill(' ') << " " << right << "|";
cout << left << setw(20) << setfill(' ') << " " << right << "|";
cout << left << setw(13) << setfill(' ') << "Total = \x9c" << totalFlightsPrice << right << "|";
cout << left << setw(6) << setfill(' ') << totalhours << "hr(s) " << totalmins << "min(s)"
<< setw(11) << setfill(' ') << right << "|" << endl;
cout << "----------------------------------------------------------------------------------------" << endl;
}
else{
int totalmins = totalFlightDuration;
int totalhours = 0;
while(totalmins >= 60){
totalhours++;
totalmins -= 60;
}
cout << left << setw(4) << setfill(' ') << " " << right << "|";
cout << left << setw(7) << setfill(' ') << " " << right << "|";
cout << left << setw(12) << setfill(' ') << " " << right << "|";
cout << left << setw(20) << setfill(' ') << " " << right << "|";
cout << left << setw(13) << setfill(' ') << "Total = \x9c" << totalFlightsPrice << right << "|";
cout << left << setw(6) << setfill(' ') << totalhours << "hr(s) " << totalmins << "min(s)"
<< setw(11) << setfill(' ') << right << "|" << endl;
cout << "----------------------------------------------------------------------------------------" << endl;
}
}
else{
cout << "----------------------------------------------------------------------------------------" << endl;
}
}
else{
cout << "No possible flight paths between the airports inputted.";
}
currentLine++;
if(filePointers[currentLine] != filePointers[currentLine - 1]){
flights.clear();
flights.seekg(filePointers[currentLine],ios::beg);
}
}
编辑： 您还可以忽略checkNumOfLines文件以及filePointers和lengthOfLines数组。我以为我必须重置文件指针才能正确打印出来，但是没有。刚刚意识到它确实输出了一条可能的飞行路径，即如果我从我正在读入程序的飞行路径输入第一个原点和目的地。
编辑2： 这给了我比应有的压力更大的压力。我认为我使用的整个方法是荒谬的。有人可以简要介绍一下他们建立一个命令行程序的方法，该程序会向您显示两个用户输入的机场代码之间可能的航班列表，请允许最多2个站点。
新方法（感谢@PaulMcKenzie和@TonyD）：
我基本上创建了3个向量，一个用于保存文本文件中的所有可能的飞行，一个用于保存当前行程的飞行（这在每个循环中被清除），一个是用于保存系列的多维向量航班是当前旅程中的载体。
class flightSearch
{
public:
struct Flight
{
string origin;
string destination;
string airline;
int price;
int flightDuration;
};
vector<Flight> allFlights;
vector<Flight> flightsInJourney;
vector<vector <Flight> > allMatches;
Flight f;
void populateFlightsVector()
{
ifstream flightsfile("flights.txt");
while(flightsfile >> f.origin >> f.destination >> f.airline >> f.price >> f.flightDuration){
allFlights.push_back(f);
}
}
void searchForARoute(string userOrigin, string userDestination)
{
populateFlightsVector();
for(unsigned i = 0; i < allFlights.size(); i++)
{
flightsInJourney.clear();
if(allFlights[i].origin == userOrigin && allFlights[i].destination == userDestination)
{
flightsInJourney.insert(flightsInJourney.begin(), allFlights[i]);
}
allMatches.push_back(flightsInJourney);
}
for(unsigned i = 0; i < allMatches.size(); i++)
{
for(unsigned j = 0; j < allMatches[i].size(); j++){
cout << allMatches[i][j].origin << " " << allMatches[i][j].destination << " " << allMatches[i][j].airline << endl;
}
}
}
};
现在我应该可以添加一些代码来检查需要多次飞行的路线，就像我在第一次尝试时所做的那样，并将它们添加到最终的多维向量中。我已经测试了这段代码，到目前为止它似乎适用于直飞航班。随意提出看起来可能有问题的任何内容。
答案 0 :(得分：0)
使用您的最新代码，我看到的问题会导致一些问题。
首先，您不需要将flightsInJourney向量作为全局变量，因此必须重复清除searchForARoute函数中的向量。您可以将其设置为searchForARoute功能的本地功能，因为您使用它的目的是收集所有匹配的航班，然后将这些航班复制到您的allMatches向量。
其次，您在搜索功能中调用populateFlightsVector，但这不是必需的。您应该只填充一次数据文件，而不是重复填充。最好把它放在main()或类似的函数中，只调用一次来设置数据。
第三，回到searchForARoute功能，你的回路收集你找到的航班是不正确的。您应该首先收集在本地向量中找到的所有航班，然后在完成后，push_back将此向量找到的航班放到您的allMatches向量中。
简而言之，该功能可能看起来更像这样：
void searchForARoute(const string& userOrigin,
const string& userDestination)
{
vector<Flight> flightsInJourney;
for(size_t i = 0; i < allFlights.size(); i++)
{
if(allFlights[i].origin == userOrigin && allFlights[i].destination == userDestination)
flightsInJourney.push_back(allFlights[i]);
}
// push back all of the found matches
allMatches.push_back(flightsInJourney);
for(size_t i = 0; i < allMatches.size(); i++)
{
for(size_t j = 0; j < allMatches[i].size(); j++)
cout << allMatches[i][j].origin << " " << allMatches[i] [j].destination << " " << allMatches[i][j].airline << endl;
}
}