/* This program will manage virtual queues for an * ammusement park. The user can add names, take names * from the queue, or print the queue out. */ #include #include "util.h" struct virtualQueue; struct guest { string name; virtualQueue *currentQueue = nullptr; guest *next = nullptr; guest *previous = nullptr; }; struct virtualQueue { string ride; int length; guest *head = nullptr; guest *tail = nullptr; }; /* * @return Returns true and print if queue is empty, * otherwise just return false */ bool emptyQueue(virtualQueue q) { if (q.length > 0) return false; else { cout << "There is no one in line for " << q.ride << "\n" << endl; return true; } } /* * @param queue - queue to add the guest to * @newGuest - Guest to be added * This takes a queue and a guest and adds the guest to the queue * It also updates the guest by attaching the queue to the guest record */ void addToQueue(virtualQueue &queue, guest *newGuest) { newGuest->currentQueue = &queue; if (queue.length != 0) { guest *last = queue.tail; newGuest->next = last; // Set the next of the new guest last->previous = newGuest; //Set the previous of the current tail queue.tail = newGuest; // Update the tail } else { // first in line queue.tail = newGuest; queue.head = newGuest; } queue.length ++; } /* * @param - Non-empty queue * @return - Guest record for the guest first in line. * This function pops the first guess off the queue and clears the * current queue for the guest. */ guest nextGuest(virtualQueue &queue){ guest *front = queue.head; queue.head = front->previous; queue.length --; front->currentQueue = nullptr; return *front; } /* * @param - Queue to be printed * Prints out the current queue with a blank line at the end. */ void printQueue(virtualQueue &q) { if (!emptyQueue(q)) { cout << "Queue for " << q.ride << endl; guest *next = q.head; while (next) { cout << next->name << endl; next = next->previous; } cout << endl; } } /* * @return - valid menu option for action from the user */ int getMenuOption() { cout << "Select an Option from the Menu:" << endl; cout << "1 - Add name to queue" << endl; cout << "2 - Get the next rider" << endl; cout << "3 - Print entire queue for a ride" << endl; cout << "4 - Quit" << endl; int option = readInt(1, 4, ">> ", "Please enter a valid option.\n>> "); return option; } /* * @param virtualQueues - map to add rides to * This function is use to set up the program and adds a set of rides * to the queue. It uses pass by reference, so it does not need to return * a value. The rides can be added to or changed. */ void addRides(map &virtualQueues) { virtualQueue dwarf; dwarf.ride = "Seven Dwarf's Mine Ride"; dwarf.length = 0; virtualQueues["7DMR"] = dwarf; virtualQueue rise; rise.ride = "Rise of the Resistance"; rise.length = 0; virtualQueues["RISE"] = rise; virtualQueue smuggler; smuggler.ride = "Millennium Falcon – Smugglers Run"; smuggler.length = 0; virtualQueues["SMUG"] = smuggler; virtualQueue flight; flight.ride = "Avatar Flight of Passage"; flight.length = 0; virtualQueues["AFOP"] = flight; } /* * @param virtualQueues - map of available rides * @return Valid key for a ride. * This function prints out the available rides and asks for * the user to select one. The function then verifies that it is a * valid key before returning it. */ string getQueueIndex(map &virtualQueues) { cout << "Please enter the code for the ride you wish to ride" << endl; cout << "Code\tRide Name" << endl; map::iterator itr = virtualQueues.begin(); while (itr != virtualQueues.end()){ cout << itr->first << "\t" << itr->second.ride << endl; itr ++; } string choice; while (true) { choice = readLine(">> "); if (virtualQueues.find(choice) != virtualQueues.end()) break; cout << "Please enter a valid choice." << endl; } return choice; } /* * @param currGuest - Current guest to be removed from the queue they are in * This function removes a guest from the middle of the queue * so that they can be added to another queue. It also checks to update the * head and tail of the queue as needed. */ void removeFromQueue(guest *currGuest) { virtualQueue *currQ = currGuest->currentQueue; currQ->length --; if (currQ->head == currGuest) currQ->head = currGuest->previous; if (currQ->tail == currGuest) currQ->tail = currGuest->next; //wire around the queue and return false guest *ahead = currGuest->next; guest *behind = currGuest->previous; if (ahead != nullptr) ahead->previous = behind; if (behind != nullptr) behind->next = ahead; currGuest->currentQueue = nullptr; } /* * @param - guests - map of guests and the guest record * @param - currGuest - New guest to be added or updated * This function checks if they are in line, if they are, check to * see if they want to leave the line and go to a new line. If not in * line or want to go to a new line, return false. */ bool currInLine(map &guests, guest *currGuest) { string name = currGuest->name; if (guests.find(name) == guests.end()) { // New guest. guests[name] = currGuest; // add return false; } else { // Guest exists, merge existing guest, check if in line currGuest = guests[name]; if (currGuest->currentQueue == nullptr) { // Not in line return false; } else { cout << currGuest->name << " is currently in line at "; cout << currGuest->currentQueue->ride << "." << endl; string change = readLine("Would you like to change rides? (Y or N)? "); if (change == "N") return true; else { removeFromQueue(currGuest); return false; } } } } int main() { // map to hold a the queues and the quests map virtualQueues; map guests; addRides(virtualQueues); //set up while (true) { int option = getMenuOption(); if (option == 1) { // Add new guest to line guest *newGuest = new guest; newGuest->name = readLine("Please enter the name of the rider: "); // Check if they are already in line before added to a new queue if (!currInLine(guests, newGuest)) { string qIndex = getQueueIndex(virtualQueues); addToQueue(virtualQueues[qIndex], newGuest); } } else if (option == 2) { // Print next guest in line and remove from queue string qIndex = getQueueIndex(virtualQueues); if (!emptyQueue(virtualQueues[qIndex])) { cout << "Next up on " << virtualQueues[qIndex].ride << ": "; cout << nextGuest(virtualQueues[qIndex]).name << "\n" <