add csci-1200-hw-2

README.md

@@ -14,8 +14,8 @@ Then, install Hugo.
 
 For Linux:
 ```bash
-wget https://github.com/gohugoio/hugo/releases/download/v0.136.5/hugo_extended_0.136.5_linux-amd64.deb
+wget https://github.com/gohugoio/hugo/releases/download/v0.141.0/hugo_extended_0.141.0_linux-amd64.deb
-dpkg -i hugo_extended_0.136.5_linux-amd64.deb
+dpkg -i hugo_extended_0.141.0_linux-amd64.deb
 ```
 
 For MacOS:

content/en/posts/csci-1100/hw-1/index.md

@@ -10,7 +10,7 @@ author:
   email:
   avatar: /site-logo.avif
 description: This blog post provides a detailed overview of a Python programming homework assignment, which includes creating a Mad Libs game, calculating speed and pace, and generating a framed box with user-specified dimensions.
-keywords: ["Python", "programming", "homework", "Mad Libs", "speed calculation", "framed box"]
+keywords: ["Python", "Programming", "Homework", "Mad Libs", "Speed calculation", "Framed box"]
 license:
 comment: true
 weight: 0
@@ -120,8 +120,6 @@ We will test your code for the values used in our examples as well as a range of
 
 {{< link href="HW1.zip" content="HW1.zip" title="Download HW1.zip" download="HW1.zip" card=true >}}
 
-***
-
 ## Solution
 
 ### hw1_part1.py

content/en/posts/csci-1100/hw-2/index.md

@@ -182,8 +182,6 @@ Test your code well and when you are sure that it works, please submit it as a f
 
 {{< link href="HW2.zip" content="HW2.zip" title="Download HW2.zip" download="HW2.zip" card=true >}}
 
-***
-
 ## Solution
 
 ### hw2_part1.py

content/zh-cn/posts/csci-1100/hw-1/index.md

@@ -120,8 +120,6 @@ Good morning <proper name>!
 
 {{< link href="HW1.zip" content="HW1.zip" title="下载 HW1.zip" download="HW1.zip" card=true >}}
 
-***
-
 ## 参考答案
 
 ### hw1_part1.py

content/zh-cn/posts/csci-1100/hw-2/index.md

@@ -182,8 +182,6 @@ repost:
 
 {{< link href="HW2.zip" content="HW2.zip" title="下载 HW2.zip" download="HW2.zip" card=true >}}
 
-***
-
 ## 参考答案
 
 ### hw2_part1.py

content/zh-cn/posts/csci-1200/hw-2/index.md

@@ -10,7 +10,7 @@ author:
   link: https://www.jamesflare.com
   email:
   avatar: /site-logo.avif
-description: 
+description: 这篇博客文章详细介绍了如何在C++中实现一个简单的拼车应用程序，作为CSCI-1200课程作业的一部分。该实现涉及使用向量存储数据来处理乘客请求和司机取消操作，并遵循特定的输入和输出文件格式。
 keywords: ["C++", "编程", "作业", "String", "Vector", "Class"]
 license:
 comment: true
@@ -29,7 +29,7 @@ hiddenFromHomePage: false
 hiddenFromSearch: false
 hiddenFromRss: false
 hiddenFromRelated: false
-summary:
+summary: 这篇博客文章详细介绍了如何在C++中实现一个简单的拼车应用程序，作为CSCI-1200课程作业的一部分。该实现涉及使用向量存储数据来处理乘客请求和司机取消操作，并遵循特定的输入和输出文件格式。
 resources:
   - name: featured-image
     src: featured-image.jpg
@@ -396,6 +396,10 @@ A: 与 Uber 相同。保留一位小数。直接截断即可。例如，如果
   - 成员变量是公开的。 (-2)
 ````
 
+## 支持文件
+
+{{< link href="ride_sharing.7z" content="ride_sharing.7z" title="Download ride_sharing.7z" download="ride_sharing.7z" card=true >}}
+
 ## 程序设计
 
 由于这次作业比较复杂，我们在开始前最好好好构思一下怎么实现。这里我借用两种情况，也就是指令是“request”和“cancel”两种情况分别设计它们单独的流程，然后在主程序中使用这两部分。姑且把它们称作`handleRequest()`以及`handleCancel()`。
@@ -461,3 +465,829 @@ flowchart TD
 ```
 
 有了流程图我们就可以慢慢实现它们了。当然，不一定要真写`handleRequest()`和`handleCancel()`两个function。把它们的逻辑直接在`main()`中实现也是可以的，我这里只是为了思路清晰而已。
+
+此外，我们要设计两个Class，因为这是作业要求，也是为了方便我们实现功能。
+
+```mermaid
+classDiagram
+    class Rider {
+        %% 数据成员
+        - firstName : 
+        - lastName : string
+        - gender : string
+        - age : int
+        - phoneNumber : string
+        - rating : double
+        - pickupLocationName : string
+        - pickupLatitude : double
+        - pickupLongitude : double
+        - dropoffLocationName : string
+        - dropoffLatitude : double
+        - dropoffLongitude : double
+        - vehiclePref : string
+        - currentState : string
+        - driverFirstName : string
+        - driverLastName : string
+        - driverPhoneNumber : string
+
+        %% 构造函数
+        + Rider()
+
+        %% 方法
+        + getFirstName()
+        + getLastName()
+        + getGender()
+        + getAge()
+        + getPhoneNumber()
+        + getRating()
+        + getPickupLocationName()
+        + getPickupLatitude()
+        + getPickupLongitude()
+        + getDropoffLocationName()
+        + getDropoffLatitude()
+        + getDropoffLongitude()
+        + getVehiclePref()
+        + getCurrentState()
+        + getDriverFirstName()
+        + getDriverLastName()
+        + getDriverPhoneNumber()
+        + setCurrentState()
+        + setDriverInfo()
+        + toFileString()
+    }
+
+    class Driver {
+        %% 数据成员
+        - firstName : string
+        - lastName : string
+        - gender : string
+        - age : int
+        - phoneNumber : string
+        - rating : double
+        - latitude : double
+        - longitude : double
+        - vehicleType : string
+        - currentState : string
+        - riderFirstName : string
+        - riderLastName : string
+        - riderPhoneNumber : string
+
+        %% 构造函数
+        + Driver()
+
+        %% 方法
+        + getFirstName()
+        + getLastName()
+        + getGender()
+        + getAge()
+        + getPhoneNumber()
+        + getRating()
+        + getLatitude()
+        + getLongitude()
+        + getVehicleType()
+        + getCurrentState()
+        + getRiderFirstName()
+        + getRiderLastName()
+        + getRiderPhoneNumber()
+        + setCurrentState()
+        + setRiderInfo()
+        + toFileString()
+    }
+```
+
+## 踩坑内容
+
+1. 在打印`output0.txt`时，looking for 后面要跟一个 Rider 期望的vehicle。但是这个vehicle可能有元音字母，所以要判断一下，到底是用a还是an。这是一个小问题，实现起来并不复杂，但是别忘了。我用了一个function来返回a还是an。
+
+   ```cpp
+   std::string autoAAn(const std::string &word) {
+       if (word.empty()) return "";
+       if (word[0] == 'A' || word[0] == 'E' || word[0] == 'I' || word[0] == 'O' || word[0] == 'U') {
+           return "an";
+       }
+       return "a";
+   }
+   ```
+
+   然后在后面配合`<sstream>`的`ostringstream`的方式拼接从Rider Class获取的字段。下面的代码就展示以下逻辑和结构，不必较真。
+
+   ```cpp
+   #include <sstream>
+   //...
+   Rider &r = riders[rIdx]; //just consider `r` as your rider class
+   std::ostringstream msg;
+   msg << "Ride requested for rider " << r.getFirstName()
+       << ", looking for " << autoAAn(r.getVehiclePref()) << " "
+       << r.getVehiclePref() << " vehicle.\n"
+       << "Pick Up Location: " << r.getPickupLocationName()
+       << ", Drop Off Location: " << r.getDropoffLocationName() << ".\n";
+   ```
+
+2. 在处理司机状态的时候要特别小心，一旦有变化要马上更新，因为一些逻辑是依赖于司机状态的。比如当司机从`On_the_way_to_pickup`变为`Available`时，需要清空Rider关联信息，并且再自动为Rider找新司机。重新寻找司机的时候，也要避免重新找到之前已经分配过的司机。
+3. Class的变量不能是Public（作业要求）的，调用内容必须用方法，而不是直接对变量操作。
+4. 根据作业要求，我们不能用`auto`类型，这导致我不得不修改了for循环的内容，比如：
+
+   ```diff
+   void exportDrivers(const std::string &filename, const std::vector<Driver> &drivers) {
+       //...
+       std::ofstream ofs(filename);
+   -    for (const auto &d : drivers) {
+   +    for (int i = 0; i < (int)drivers.size(); i++) {
+   +        const Driver &d = drivers[i];
+           ofs << d.toFileString() << "\n";
+       }
+       ofs.close();
+   }
+   ```
+
+## 参考代码
+
+### nyrider.cpp
+
+```cpp
+//An implement of CSCI-1200 HW2 Ride Sharing
+//Author: JamesFlare
+//Date: 2025/1/20
+//#include <algorithm>
+//#include <cstdlib>
+#include <cmath>
+#include <vector>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <iostream>
+#include <iomanip>
+
+#include "Driver.h"
+#include "Rider.h"
+
+void debug_print(const std::string &msg) {
+    std::cout << "DEBUG: " << msg << std::endl;
+}
+
+bool isPhoneNumberValid(const std::string &phone)
+{
+    if (phone.size() != 12) return false;
+    //xxx-xxx-xxxx
+    for (int i = 0; i < 12; i++) {
+        if (i == 3 || i == 7) {
+            if (phone[i] != '-') return false;
+        } else {
+            if (!std::isdigit((unsigned char)phone[i])) return false;
+        }
+    }
+    return true;
+}
+
+void loadDrivers(std::ifstream &ifs, std::vector<Driver> &drivers) {
+    //read the file line by line, total of 13
+    while (!ifs.eof()) {
+        std::string fName, lName, gender, phone, vehicleType, state;
+        std::string rF, rL, rP;
+        int age;
+        double rating, lat, lon;
+        ifs >> fName >> lName >> gender >> age >> phone >> rating >> lat >> lon
+            >> vehicleType >> state >> rF >> rL >> rP;
+        if (!ifs.fail()) {
+            //change "null" to empty string
+            if (rF == "null") rF = "";
+            if (rL == "null") rL = "";
+            if (rP == "null") rP = "";
+            //create driver
+            Driver d(fName, lName, gender, age, phone, rating, lat, lon,
+                     vehicleType, state, rF, rL, rP);
+            drivers.push_back(d);
+        }
+    }
+    ifs.close();
+}
+
+void loadRiders(std::ifstream &ifs, std::vector<Rider> &riders) {
+    //read the file line by line, total of 17
+    while (!ifs.eof()) {
+        std::string fName, lName, gender, phone, pickupLoc, dropoffLoc, vPref, state;
+        std::string dF, dL, dP;
+        int age;
+        double rating, pickupLat, pickupLon, dropoffLat, dropoffLon;
+        ifs >> fName >> lName >> gender >> age >> phone >> rating
+            >> pickupLoc >> pickupLat >> pickupLon
+            >> dropoffLoc >> dropoffLat >> dropoffLon
+            >> vPref >> state
+            >> dF >> dL >> dP;
+        if (!ifs.fail()) {
+            //fill null with empty string
+            if (dF == "null") dF = "";
+            if (dL == "null") dL = "";
+            if (dP == "null") dP = "";
+            //create rider
+            Rider r(fName, lName, gender, age, phone, rating,
+                    pickupLoc, pickupLat, pickupLon,
+                    dropoffLoc, dropoffLat, dropoffLon,
+                    vPref, state, dF, dL, dP);
+            riders.push_back(r);
+        }
+    }
+    ifs.close();
+}
+
+std::ifstream loadFile(const std::string &filename) {
+    //read file and return ifstream
+    std::ifstream ifs(filename);
+    if (!ifs) {
+        std::cerr << "Error opening file: " << filename << std::endl;
+        exit(1);
+    }
+    return ifs;
+}
+
+void saveFile(const std::string &filename, const std::string &msg) {
+    std::ofstream ofs(filename);
+    if (!ofs) {
+        std::cerr << "Error opening file: " << filename << std::endl;
+        exit(1);
+    }
+    ofs << msg;
+    ofs.close();
+}
+
+void exportDrivers(const std::string &filename, const std::vector<Driver> &drivers) {
+    //save drivers to file
+    std::ofstream ofs(filename);
+    if (!ofs) {
+        std::cerr << "Error opening output file: " << filename << std::endl;
+        return;
+    }
+    for (int i = 0; i < (int)drivers.size(); i++) {
+        const Driver &d = drivers[i];
+        ofs << d.toFileString() << "\n";
+    }
+    ofs.close();
+}
+
+void exportRiders(const std::string &filename, const std::vector<Rider> &riders) {
+    //save riders to file
+    std::ofstream ofs(filename);
+    if (!ofs) {
+        std::cerr << "Error opening output file: " << filename << std::endl;
+        return;
+    }
+    for (int i = 0; i < (int)riders.size(); i++) {
+        const Rider &r = riders[i];
+        ofs << r.toFileString() << "\n";
+    }
+    ofs.close();
+}
+
+// calculate the distance between two coordinates using Haversine formula
+double calculateDistance(double lat1, double lon1, double lat2, double lon2) {
+    const double radiusOfEarth = 6371.0; // Earth's radius in kilometers
+    // convert latitude and longitude from degrees to radians
+    lat1 *= M_PI / 180.0;
+    lon1 *= M_PI / 180.0;
+    lat2 *= M_PI / 180.0;
+    lon2 *= M_PI / 180.0;
+    // Haversine formula
+    double dLat = lat2 - lat1;
+    double dLon = lon2 - lon1;
+    double a = sin(dLat / 2.0) * sin(dLat / 2.0) + cos(lat1) * cos(lat2) * sin(dLon / 2.0) * sin(dLon / 2.0);
+    double c = 2.0 * atan2(sqrt(a), sqrt(1.0 - a));
+    // distance in kilometers
+    double distanceKM = radiusOfEarth * c;
+    // convert it to distance in miles
+    double distanceMiles = distanceKM * 0.621371;
+
+    return distanceMiles;
+}
+
+int findClosestDriver(const std::vector<Driver> &drivers,
+                      const Rider &rider) {
+    double minDistance = 1e9;
+    int bestIndex = -1;
+    for (int i = 0; i < (int)drivers.size(); i++) {
+        const Driver &drv = drivers[i];
+        if (drv.getCurrentState() == "Available" &&
+            drv.getVehicleType() == rider.getVehiclePref()) {
+            double dist = calculateDistance(drv.getLatitude(), drv.getLongitude(),
+                                            rider.getPickupLatitude(), rider.getPickupLongitude());
+            if (dist < minDistance) {
+                minDistance = dist;
+                bestIndex = i;
+            }
+        }
+    }
+    return bestIndex;
+}
+
+int findRiderIndexByPhone(const std::vector<Rider> &riders, const std::string &phone) {
+    for (int i = 0; i < (int)riders.size(); i++) {
+        if (riders[i].getPhoneNumber() == phone) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int findDriverIndexByPhone(const std::vector<Driver> &drivers, const std::string &phone) {
+    for (int i = 0; i < (int)drivers.size(); i++) {
+        if (drivers[i].getPhoneNumber() == phone) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+std::string autoAAn(const std::string &word) {
+    if (word.empty()) return "";
+    if (word[0] == 'A' || word[0] == 'E' || word[0] == 'I' || word[0] == 'O' || word[0] == 'U') {
+        return "an";
+    }
+    return "a";
+}
+
+int main(int argc, char *argv[]) {
+    //take 3 arguments
+    if (argc < 8) {
+        std::cout << "Usage: nyride drivers.txt riders.txt output0.txt output1.txt output2.txt phoneNumber [request|cancel]\n" << std::endl;
+        return 1;
+    }
+    //load arguments
+    const std::string drivers_fName = argv[1];
+    const std::string riders_fName = argv[2];
+    std::string msg_fName = argv[3];
+    std::string updated_drivers_fName = argv[4];
+    std::string updated_riders_fName = argv[5];
+    std::string phone_number = argv[6];
+    std::string command = argv[7];
+    //turn on debug mode is last argument is debug
+    bool debug_mode = false;
+    if (std::string(argv[argc - 1]) == "debug") {
+        debug_mode = true;
+    }
+
+    if (debug_mode) {
+        debug_print("drivers_fName = " + drivers_fName);
+        debug_print("riders_fName = " + riders_fName);
+        debug_print("msg_fName = " + msg_fName);
+        debug_print("updated_drivers_fName = " + updated_drivers_fName);
+        debug_print("updated_riders_fName = " + updated_riders_fName);
+        debug_print("phone_number = " + phone_number);
+        debug_print("command = " + command);
+    }
+    //load drivers
+    std::vector<Driver> drivers;
+    std::ifstream drivers_file = loadFile(drivers_fName);
+    loadDrivers(drivers_file, drivers);
+    //load riders
+    std::vector<Rider> riders;
+    std::ifstream riders_file = loadFile(riders_fName);
+    loadRiders(riders_file, riders);
+    if (debug_mode) {
+        debug_print("drivers.size() = " + std::to_string(drivers.size()));
+        debug_print("riders.size() = " + std::to_string(riders.size()));
+    }
+    //check if phone number is valid
+    std::ostringstream msg;
+    if (!isPhoneNumberValid(phone_number)) {
+        std::cout << "Error: Invalid phone number" << std::endl;
+        msg << "Phone number is invalid.\n";
+        saveFile(msg_fName, msg.str());
+        return 1;
+    }
+    //check if command is valid
+    if (command != "request" && command != "cancel") {
+        std::cout << "Error: Invalid command" << std::endl;
+        return 1;
+    } else if (command == "request") {
+        //for request cases
+        int rIdx = findRiderIndexByPhone(riders, phone_number);
+        if (rIdx == -1) {
+            //if rider does not exist
+            msg << "Account does not exist.\n";
+            saveFile(msg_fName, msg.str());
+            return 1;
+        }
+        Rider &r = riders[rIdx];
+        //check rider
+        if (r.getCurrentState() == "Driver_on_the_way") {
+            msg << "You have already requested a ride and your driver is on the way to the pickup location.\n";
+            saveFile(msg_fName, msg.str());
+            return 1;
+        }
+        if (r.getCurrentState() == "During_the_trip") {
+            msg << "You can not request a ride at this moment as you are already on a trip.\n";
+            saveFile(msg_fName, msg.str());
+            return 1;
+        }
+        if (r.getCurrentState() == "Ready_to_request") {
+            msg << "Ride requested for rider " << r.getFirstName()
+                << ", looking for " << autoAAn(r.getVehiclePref()) << " "
+                << r.getVehiclePref() << " vehicle.\n"
+                << "Pick Up Location: " << r.getPickupLocationName()
+                << ", Drop Off Location: " << r.getDropoffLocationName() << ".\n";
+            //find closest driver
+            int dIdx = findClosestDriver(drivers, r);
+            if (dIdx == -1) {
+                //no driver
+                msg << "Sorry we can not find a driver for you at this moment.\n";
+            } else {
+                Driver &d = drivers[dIdx];
+                double dist = calculateDistance(d.getLatitude(), d.getLongitude(),
+                                                r.getPickupLatitude(), r.getPickupLongitude());
+                dist = (int)(dist * 10) / 10.0; //cut to 1 decimal
+                msg << "We have found the closest driver " << d.getFirstName() << "("
+                    << std::fixed << std::setprecision(1) << d.getRating() << ") for you.\n"
+                    << d.getFirstName() << " is now " 
+                    << std::fixed << std::setprecision(1) << dist 
+                    << " miles away from you.\n";
+                //update status
+                d.setCurrentState("On_the_way_to_pickup");
+                d.setRiderInfo(r.getFirstName(), r.getLastName(), r.getPhoneNumber());
+                r.setCurrentState("Driver_on_the_way");
+                r.setDriverInfo(d.getFirstName(), d.getLastName(), d.getPhoneNumber());
+            }
+        }
+    } else if (command == "cancel") {
+        //for cancel cases
+        //find phone_number in riders
+        int rIdx = findRiderIndexByPhone(riders, phone_number);
+        if (rIdx == -1) {
+            //in case of driver's cancel
+            int dIdx = findDriverIndexByPhone(drivers, phone_number);
+            if (dIdx == -1) {
+                //in case of not both rider and driver
+                msg << "Account does not exist.\n";
+                saveFile(msg_fName, msg.str());
+                return 1;
+            }
+            Driver &driver = drivers[dIdx];
+            if (driver.getCurrentState() != "On_the_way_to_pickup") {
+                msg << "You can only cancel a ride request if you are currently on the way to the pickup location.\n";
+                saveFile(msg_fName, msg.str());
+                return 1;
+            }
+            //get rider's phone number
+            std::string rPh = driver.getRiderPhoneNumber();
+            //clean driver's rider info
+            driver.setCurrentState("Available");
+            driver.setRiderInfo("", "", "");
+            msg << "Your driver " << driver.getFirstName()
+                << " has canceled the ride request. We will now find a new driver for you.\n";
+            //find rider
+            int theRiderIdx = findRiderIndexByPhone(riders, rPh);
+            Rider &r = riders[theRiderIdx];
+            //reset rider
+            r.setCurrentState("Ready_to_request");
+            r.setDriverInfo("", "", "");
+            //find a new driver
+            msg << "Ride requested for rider " << r.getFirstName()
+                << ", looking for " << autoAAn(r.getVehiclePref()) << " "
+                << r.getVehiclePref() << " vehicle.\n"
+                << "Pick Up Location: " << r.getPickupLocationName()
+                << ", Drop Off Location: " << r.getDropoffLocationName() << ".\n";
+            int newDIdx = findClosestDriver(drivers, r);
+            if (newDIdx == -1) {
+                msg << "Sorry we can not find a driver for you at this moment.\n";
+            } else {
+                Driver &newDriver = drivers[newDIdx];
+                double dist = calculateDistance(newDriver.getLatitude(), newDriver.getLongitude(),
+                                                r.getPickupLatitude(), r.getPickupLongitude());
+                dist = (int)(dist * 10) / 10.0; //cut to 1 decimal
+                msg << "We have found the closest driver " << newDriver.getFirstName() << "("
+                    << std::fixed << std::setprecision(1) << newDriver.getRating() << ") for you.\n"
+                    << newDriver.getFirstName() << " is now " 
+                    << std::fixed << std::setprecision(1) << dist 
+                    << " miles away from you.\n";
+                //update driver's status
+                newDriver.setCurrentState("On_the_way_to_pickup");
+                newDriver.setRiderInfo(r.getFirstName(), r.getLastName(), r.getPhoneNumber());
+                //update rider's status
+                r.setCurrentState("Driver_on_the_way");
+                r.setDriverInfo(newDriver.getFirstName(), newDriver.getLastName(), newDriver.getPhoneNumber());
+            }
+        } else {
+            //in case of rider's cancel
+            Rider &rider = riders[rIdx];
+            if (rider.getCurrentState() != "Driver_on_the_way") {
+                msg << "You can only cancel a ride request if your driver is currently on the way to the pickup location.\n";
+                saveFile(msg_fName, msg.str());
+                return 1;
+            }
+            //find driver's phone_number
+            std::string dPh = rider.getDriverPhoneNumber();
+            msg << "Ride request for rider " << rider.getFirstName()
+                << " is now canceled by the rider.\n";
+            //set driver's status to Available
+            int dIdx = findDriverIndexByPhone(drivers, dPh);
+            if (dIdx != -1) {
+                Driver &drv = drivers[dIdx];
+                drv.setCurrentState("Available");
+                drv.setRiderInfo("", "", "");
+            }
+            //set rider's status to Ready_to_request
+            rider.setCurrentState("Ready_to_request");
+            rider.setDriverInfo("", "", "");
+        }
+    }
+    //save msg
+    saveFile(msg_fName, msg.str());
+    //save updated drivers and riders
+    exportDrivers(updated_drivers_fName, drivers);
+    exportRiders(updated_riders_fName, riders);
+
+    return 0;
+}
+```
+
+### Rider.h
+
+```cpp
+#ifndef __RIDER_H
+#define __RIDER_H
+
+#include <string>
+
+class Rider {
+private:
+    std::string firstName;
+    std::string lastName;
+    std::string gender;
+    int age;
+    std::string phoneNumber;
+    double rating;
+    std::string pickupLocationName;
+    double pickupLatitude;
+    double pickupLongitude;
+    std::string dropoffLocationName;
+    double dropoffLatitude;
+    double dropoffLongitude;
+    std::string vehiclePref;
+    std::string currentState;
+    //driver's info
+    std::string driverFirstName;
+    std::string driverLastName;
+    std::string driverPhoneNumber;
+
+public:
+    //init
+    Rider();
+    Rider(const std::string &fName, const std::string &lName,
+          const std::string &gen, int a, const std::string &phone,
+          double r, const std::string &pickupLocName, double pickupLat, double pickupLon,
+          const std::string &dropoffLocName, double dropoffLat, double dropoffLon,
+          const std::string &vehiclePref, const std::string &state,
+          const std::string &dF, const std::string &dL, const std::string &dP);
+
+    //getters & setters
+    const std::string& getFirstName() const;
+    const std::string& getLastName() const;
+    const std::string& getGender() const;
+    int getAge() const;
+    const std::string& getPhoneNumber() const;
+    double getRating() const;
+    const std::string& getPickupLocationName() const;
+    double getPickupLatitude() const;
+    double getPickupLongitude() const;
+    const std::string& getDropoffLocationName() const;
+    double getDropoffLatitude() const;
+    double getDropoffLongitude() const;
+    const std::string& getVehiclePref() const;
+    const std::string& getCurrentState() const;
+    const std::string& getDriverFirstName() const;
+    const std::string& getDriverLastName() const;
+    const std::string& getDriverPhoneNumber() const;
+
+    void setCurrentState(const std::string &state);
+    void setDriverInfo(const std::string &df, const std::string &dl, const std::string &dp);
+    //return a string representation of the rider
+    std::string toFileString() const;
+};
+
+#endif
+```
+
+### Rider.cpp
+
+```cpp
+#include "Rider.h"
+#include <sstream>
+
+Rider::Rider()
+ : age(0), rating(0.0), pickupLatitude(0.0), pickupLongitude(0.0),
+   dropoffLatitude(0.0), dropoffLongitude(0.0) {}
+
+Rider::Rider(const std::string &fName, const std::string &lName,
+             const std::string &gen, int a, const std::string &phone,
+             double r, const std::string &pickupLocName, double pickupLat, double pickupLon,
+             const std::string &dropoffLocName, double dropoffLat, double dropoffLon,
+             const std::string &vPref, const std::string &state,
+             const std::string &dF, const std::string &dL, const std::string &dP)
+ : firstName(fName), lastName(lName), gender(gen), age(a),
+   phoneNumber(phone), rating(r),
+   pickupLocationName(pickupLocName), pickupLatitude(pickupLat), pickupLongitude(pickupLon),
+   dropoffLocationName(dropoffLocName), dropoffLatitude(dropoffLat), dropoffLongitude(dropoffLon),
+   vehiclePref(vPref), currentState(state),
+   driverFirstName(dF), driverLastName(dL), driverPhoneNumber(dP) {}
+
+const std::string& Rider::getFirstName() const { return firstName; }
+const std::string& Rider::getLastName() const { return lastName; }
+const std::string& Rider::getGender() const { return gender; }
+int Rider::getAge() const { return age; }
+const std::string& Rider::getPhoneNumber() const { return phoneNumber; }
+double Rider::getRating() const { return rating; }
+const std::string& Rider::getPickupLocationName() const { return pickupLocationName; }
+double Rider::getPickupLatitude() const { return pickupLatitude; }
+double Rider::getPickupLongitude() const { return pickupLongitude; }
+const std::string& Rider::getDropoffLocationName() const { return dropoffLocationName; }
+double Rider::getDropoffLatitude() const { return dropoffLatitude; }
+double Rider::getDropoffLongitude() const { return dropoffLongitude; }
+const std::string& Rider::getVehiclePref() const { return vehiclePref; }
+const std::string& Rider::getCurrentState() const { return currentState; }
+const std::string& Rider::getDriverFirstName() const { return driverFirstName; }
+const std::string& Rider::getDriverLastName() const { return driverLastName; }
+const std::string& Rider::getDriverPhoneNumber() const { return driverPhoneNumber; }
+
+void Rider::setCurrentState(const std::string &state) {
+    currentState = state;
+}
+
+void Rider::setDriverInfo(const std::string &df, const std::string &dl, const std::string &dp) {
+    driverFirstName = df;
+    driverLastName = dl;
+    driverPhoneNumber = dp;
+}
+
+std::string Rider::toFileString() const {
+    //Isabella
+    //Richard
+    //Female
+    //39
+    //301-144-6533
+    //3.2
+    //Top_of_the_Rock
+    //40.7593 -73.979
+    //Gowanus
+    //40.6733
+    //-73.99
+    //Economy
+    //Ready_to_request
+    //null
+    //null
+    //null
+    std::ostringstream oss;
+    oss << firstName << " "
+        << lastName << " "
+        << gender << " "
+        << age << " "
+        << phoneNumber << " "
+        << rating << " "
+        << pickupLocationName << " "
+        << pickupLatitude << " "
+        << pickupLongitude << " "
+        << dropoffLocationName << " "
+        << dropoffLatitude << " "
+        << dropoffLongitude << " "
+        << vehiclePref << " "
+        << currentState << " "
+        << (driverFirstName.empty() ? "null" : driverFirstName) << " "
+        << (driverLastName.empty() ? "null" : driverLastName) << " "
+        << (driverPhoneNumber.empty() ? "null" : driverPhoneNumber);
+
+    return oss.str();
+}
+```
+
+### Driver.h
+
+```cpp
+#ifndef __DRIVER_H
+#define __DRIVER_H
+
+#include <string>
+
+class Driver {
+private:
+    std::string firstName;
+    std::string lastName;
+    std::string gender;
+    int age;
+    std::string phoneNumber;
+    double rating;
+    double latitude;
+    double longitude;
+    std::string vehicleType;
+    std::string currentState;
+    //rider's info
+    std::string riderFirstName;
+    std::string riderLastName;
+    std::string riderPhoneNumber;
+
+public:
+    //init
+    Driver();
+    Driver(const std::string &firstName, const std::string &lastName,
+           const std::string &gender, int age, const std::string &phoneNumber,
+           double rating, double latitude, double longitude,
+           const std::string &vehicleType, const std::string &currentState,
+           const std::string &riderFirstName, const std::string &riderLastName,
+           const std::string &riderPhoneNumber);
+
+    //getters & setters
+    const std::string& getFirstName() const;
+    const std::string& getLastName() const;
+    const std::string& getGender() const;
+    int getAge() const;
+    const std::string& getPhoneNumber() const;
+    double getRating() const;
+    double getLatitude() const;
+    double getLongitude() const;
+    const std::string& getVehicleType() const;
+    const std::string& getCurrentState() const;
+    const std::string& getRiderFirstName() const;
+    const std::string& getRiderLastName() const;
+    const std::string& getRiderPhoneNumber() const;
+
+    void setCurrentState(const std::string &state);
+    void setRiderInfo(const std::string &rf, const std::string &rl, const std::string &rp);
+    //return a string representation of the driver
+    std::string toFileString() const;
+};
+
+#endif
+```
+
+### Driver.cpp
+
+```cpp
+#include "Driver.h"
+#include <sstream>
+
+Driver::Driver() : age(0), rating(0.0), latitude(0.0), longitude(0.0) {}
+
+Driver::Driver(const std::string &fName, const std::string &lName,
+               const std::string &gen, int a, const std::string &phone,
+               double r, double lat, double lon,
+               const std::string &vehType, const std::string &state,
+               const std::string &rF, const std::string &rL,
+               const std::string &rP)
+ : firstName(fName), lastName(lName), gender(gen), age(a),
+   phoneNumber(phone), rating(r), latitude(lat), longitude(lon),
+   vehicleType(vehType), currentState(state),
+   riderFirstName(rF), riderLastName(rL), riderPhoneNumber(rP) {}
+
+//getters
+const std::string& Driver::getFirstName() const { return firstName; }
+const std::string& Driver::getLastName() const { return lastName; }
+const std::string& Driver::getGender() const { return gender; }
+int Driver::getAge() const { return age; }
+const std::string& Driver::getPhoneNumber() const { return phoneNumber; }
+double Driver::getRating() const { return rating; }
+double Driver::getLatitude() const { return latitude; }
+double Driver::getLongitude() const { return longitude; }
+const std::string& Driver::getVehicleType() const { return vehicleType; }
+const std::string& Driver::getCurrentState() const { return currentState; }
+const std::string& Driver::getRiderFirstName() const { return riderFirstName; }
+const std::string& Driver::getRiderLastName() const { return riderLastName; }
+const std::string& Driver::getRiderPhoneNumber() const { return riderPhoneNumber; }
+
+//setters
+void Driver::setCurrentState(const std::string &state) {
+    currentState = state;
+}
+
+void Driver::setRiderInfo(const std::string &rf, const std::string &rl, const std::string &rp) {
+    riderFirstName = rf;
+    riderLastName = rl;
+    riderPhoneNumber = rp;
+}
+
+std::string Driver::toFileString() const {
+    //Sandra
+    //Huang
+    //Female
+    //25
+    //853-977-5304  
+    //3.1
+    //40.4269
+    //-73.0753
+    //Standard
+    //On_the_way_to_pickup
+    //Michael
+    //Richard
+    //445-915-1645
+    std::ostringstream oss;
+    oss << firstName << " "
+        << lastName << " "
+        << gender << " "
+        << age << " "
+        << phoneNumber << " "
+        << rating << " "
+        << latitude << " "
+        << longitude << " "
+        << vehicleType << " "
+        << currentState << " "
+        << (riderFirstName.empty() ? "null" : riderFirstName) << " "
+        << (riderLastName.empty() ? "null" : riderLastName) << " "
+        << (riderPhoneNumber.empty() ? "null" : riderPhoneNumber);
+    return oss.str();
+}
+```