diff --git a/Team 20-TrashCash/README.md b/Team 20-TrashCash/README.md
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+++ b/Team 20-TrashCash/README.md	
@@ -0,0 +1,6 @@
+Problem Statement:
+A Model based on Dry Waste Management System which consists of two interfaces user and volunteer, where a volunteer is assigned to user to collect the dry waste and the user is paid according to the weight of segregated dry waste.
+Data Structure Used:
+We used Queue as a data structure.
+Drive Link to reports and video:
+https://drive.google.com/drive/folders/1AEdTj5PMvtC9BA8CNmfYfHoB7Ha3nsv_?usp=drive_link
diff --git a/TrashCash.java b/TrashCash.java
new file mode 100644
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--- /dev/null
+++ b/TrashCash.java
@@ -0,0 +1,493 @@
+package Buffer;
+
+
+import java.util.*;
+import java.util.ArrayList;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.List;
+import java.io.*;
+//import java.util.Arrays;
+
+class User implements Serializable {
+    private String username;
+    private String password;
+    //private String uadd;
+
+    public User(String username, String password) {
+        this.username = username;
+        this.password = password;
+        //this.uadd=uadd;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+    
+
+   
+}
+
+class Vol implements Serializable {
+    private String volname;
+    private String vol_password;
+    private List<String> preferredAreas;
+   // private List<String> preferredAreas;
+   private User assignedUser;
+    public Vol(String volname, String vol_password,List<String> preferredAreas) {
+        this.volname = volname;
+        this.vol_password = vol_password;
+       // this.preferredAreas = preferredAreas;
+       this.preferredAreas = preferredAreas;
+    }
+
+    public String getVolname() {
+        return volname;
+    }
+
+    public String getVPassword() {
+        return vol_password;
+    }
+    public List<String> getPreferredAreas() {
+        return preferredAreas;
+    }
+    public User getAssignedUser() {
+        return assignedUser;
+    }
+
+    public void setAssignedUser(User assignedUser) {
+        this.assignedUser = assignedUser;
+    }
+}
+
+ class Trashcash {
+    private static final String USER_DATA_FILE = "users.dat";
+    private static final String VOL_DATA_FILE = "vol.dat";
+    private static List<User> users = new ArrayList<>();
+    private static List<Vol> vol = new ArrayList<>();
+    private static VolunteerQueueManager volunteerQueueManager = new VolunteerQueueManager();
+    public static final String ANSI_RESET="\u001B[0m";
+    public static final String ANSI_BOLD="\u001B[1m";private int value;
+
+    public static void main(String[] args) {
+        loadUsers();
+        loadVol();
+        for (Vol volunteer : vol) {
+            volunteerQueueManager.addVolunteer(volunteer);
+        }
+        Scanner sc = new Scanner(System.in);
+
+        System.out.println(     ANSI_BOLD+"Welcome to TrashCash!"+ANSI_RESET     );
+        System.out.println("Are you a "+ANSI_BOLD+"user"+ANSI_RESET+" or a "+ANSI_BOLD+"volunteer"+ANSI_RESET+"(1 for user and 2 for volunteer)");
+        int ch2 = sc.nextInt();
+        sc.nextLine(); // Consume newline left-over
+
+        // Registration loop
+        while (true) {
+            if (ch2 == 1) {
+                System.out.println();
+                System.out.println(ANSI_BOLD+"USER PROFILE"+ANSI_RESET);
+                System.out.print("  Enter a username: ");
+                String username = sc.nextLine();
+                if (usernameExists(username)) {
+                    System.out.print("  Username already exists. Do you want to log in?"+ANSI_BOLD+"(yes/no):"+ANSI_RESET);
+                    String choice = sc.nextLine().toLowerCase();
+                    if (choice.equals("yes")) {
+                        if (loginUser(sc, username)) {
+                            
+                            break; // Exit the loop since login is successful
+                        }
+                    } else {
+                        continue; // Go to the beginning of the loop to retry registration
+                    }
+                } else {
+                    System.out.print("  Enter a password: ");
+                    String password = sc.nextLine();
+                    User newUser = new User(username, password);
+                    users.add(newUser);
+                    saveUsers();
+                    System.out.print(ANSI_BOLD+"  Registration successful for user: " + username+ANSI_RESET+"\n");
+                    // Exit the loop since registration is successful
+            
+                    break;
+                }
+            } else if (ch2 == 2) {
+                System.out.println(ANSI_BOLD+"VOLUNTEER PROFILE"+ANSI_RESET);
+                System.out.print("  Enter a username: ");
+                String volname = sc.nextLine();
+                if (volExists(volname)) {
+                    System.out.print("  Username already exists. Do you want to log in? "+ANSI_BOLD+"(yes/no):"+ANSI_RESET);
+                    String choice = sc.nextLine().toLowerCase();
+                    if (choice.equals("yes")) {
+                        if (loginVol(sc, volname)) {
+                            break; // Exit the loop since login is successful
+                        }
+                    } else {
+                        continue; // Go to the beginning of the loop to retry registration
+                    }
+                } else {
+                    System.out.print("  Enter a password: ");
+                    String vol_password = sc.nextLine();
+        List<String> preferredAreas = new ArrayList<>();
+        
+        System.out.print("  Enter your preferred areas,separated by commas:");
+        String areasInput = sc.nextLine();
+        String[] areasArray = areasInput.split(",");
+        preferredAreas.addAll(Arrays.asList(areasArray));
+
+                    // Create a new user profile and add it to the list
+                    Vol newVol = new Vol(volname, vol_password, preferredAreas);
+                    
+                    vol.add(newVol);
+                    saveVol();
+                    System.out.println(ANSI_BOLD+"  Registration successful for volunteer: " + volname+ANSI_RESET);
+                    // Exit the loop since registration is successful
+                    break;
+                }
+        
+            }
+        }
+
+        // After successful registration/login
+        if (ch2 == 1) {
+            // Booking appointment
+            System.out.print("  Do you want to book an appointment? "+ANSI_BOLD+"(yes/no):"+ANSI_RESET);
+            String bookAppointment = sc.nextLine().toLowerCase();
+            if (bookAppointment.equals("yes")) {
+                System.out.println();
+                System.out.print(ANSI_BOLD+"  Choose the dry waste items you want to dispose:"+ANSI_RESET+"\n");
+                Map<Integer, String> dryWastes = new HashMap<>();
+                dryWastes.put(1, "Newspaper/books/Magazines");
+                dryWastes.put(2, "Plastic No. 1-bottles, clothing, carpet fibers, and packaging materials.");
+                dryWastes.put(3, "Plastic No. 2-milk jugs, detergent bottles, household cleaner bottles, plastic bags, and plastic lumber.");
+                dryWastes.put(4, "Plastic No. 3-pipes and fittings, vinyl siding, window frames, flooring, medical tubing, and credit cards.");
+                dryWastes.put(5, "Tyres and tubes");
+                dryWastes.put(6, "Rubber seals and gaskets");
+                dryWastes.put(7, "Rubber toys and sporting goods");
+                dryWastes.put(8, "Rubberised fibres and textiles");
+                dryWastes.put(9, "Rubber hoses and tubing");
+                dryWastes.put(10, "Thermocol");
+                dryWastes.put(11, "Styrofoam");
+                dryWastes.put(12, "Aluminium cans");
+                dryWastes.put(13, "Clear Glass bottles");
+                dryWastes.put(14, "Colored Glass bottles");
+            
+                // Displaying dry waste items
+                for (Integer key : dryWastes.keySet()) {
+                    System.out.println(key + ". " + dryWastes.get(key));
+                }
+            
+                List<String> selectedItems = new ArrayList<>();
+                boolean validInput = false;
+                Map<String, Float> weightsMap = new HashMap<>();
+                while (!validInput) {
+                    // Handling user selection
+                    System.out.print("  Enter the serial numbers of the items you want to dispose (comma-separated):");
+                    String choicesInput = sc.nextLine();
+                    String[] choicesArray = choicesInput.split(",");
+                    selectedItems.clear();
+            
+                    for (String choiceStr : choicesArray) {
+                        int choice;
+                        try {
+                            choice = Integer.parseInt(choiceStr.trim());
+                        } catch (NumberFormatException e) {
+                            System.out.println("  Invalid input. Please enter comma-separated serial numbers.");
+                            validInput = false;
+                            break;
+                        }
+            
+                        if (choice >= 1 && choice <= dryWastes.size()) {
+                            selectedItems.add(dryWastes.get(choice));
+                            validInput = true;
+                        } else {
+                            System.out.println("  Invalid choice: " + choice);
+                            validInput = false;
+                            break;
+                        }
+                    }
+            
+                    if (validInput) {
+                        // Print selected items in the specified format
+                        System.out.println(ANSI_BOLD+"  You selected:"+ANSI_RESET);
+                        for (String item : selectedItems) {
+                            System.out.println("   - " + item);
+                        }
+                        
+                     float cost=0;
+                        for (String item1 : selectedItems){
+                           System.out.print("  Enter the weight for "+ANSI_BOLD+item1+ANSI_RESET+"(in kg): ");
+                           float w=sc.nextFloat();
+                           weightsMap.put(item1, w);
+                        }
+
+                        float w1; 
+                        System.out.println("\n  The "+ANSI_BOLD+"approximate amount "+ANSI_RESET+"you will get in return for the given dry waste:");
+                       if(weightsMap.containsKey("Newspaper/books/Magazines")){
+                        w1=weightsMap.get("Newspaper/books/Magazines");
+                        System.out.println("   Newspaper/books/Magazines:"+ANSI_BOLD+(w1*5 ) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*5);
+                       }
+                       if(weightsMap.containsKey("Plastic No. 1-bottles, clothing, carpet fibers, and packaging materials.")){
+                        w1=weightsMap.get("Plastic No. 1-bottles, clothing, carpet fibers, and packaging materials.");
+                        System.out.println("   Plastic No. 1-bottles, clothing, carpet fibers, and packaging materials.:"+ANSI_BOLD+(w1*18 ) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*18);
+                       }
+                       if(weightsMap.containsKey("Plastic No. 2-milk jugs, detergent bottles, household cleaner bottles, plastic bags, and plastic lumber.")){
+                        w1=weightsMap.get("Plastic No. 2-milk jugs, detergent bottles, household cleaner bottles, plastic bags, and plastic lumber.");
+                        System.out.println("   Plastic No. 2-milk jugs, detergent bottles, household cleaner bottles, plastic bags, and plastic lumber.:"+ANSI_BOLD+(w1*13 ) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*13);
+                       }
+                       if(weightsMap.containsKey("Plastic No. 3-pipes and fittings, vinyl siding, window frames, flooring, medical tubing, and credit cards.")){
+                        w1=weightsMap.get("Plastic No. 3-pipes and fittings, vinyl siding, window frames, flooring, medical tubing, and credit cards.");
+                        System.out.println("   Plastic No. 3-pipes and fittings, vinyl siding, window frames, flooring, medical tubing, and credit cards.:"+ANSI_BOLD+(w1*10 ) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*10);
+                       }
+                       if(weightsMap.containsKey("Tyres and tubes")){
+                        w1=weightsMap.get("Tyres and tubes");
+                        System.out.println("   Tyres and tubes:"+ANSI_BOLD+(w1*30) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*30);
+                       }
+                       if(weightsMap.containsKey("Rubber seals and gaskets")){
+                        w1=weightsMap.get("Rubber seals and gaskets");
+                        System.out.println("   Rubber seals and gaskets:"+ANSI_BOLD+(w1*6 ) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*6);
+                       }
+                       if(weightsMap.containsKey("Rubber toys and sporting goods")){
+                        w1=weightsMap.get("Rubber toys and sporting goods");
+                        System.out.println("   Rubber toys and sporting goods:"+ANSI_BOLD+(w1*24) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*24);
+                       }
+                       if(weightsMap.containsKey("Rubber hoses and tubing")){
+                        w1=weightsMap.get("Rubber hoses and tubing");
+                        System.out.println("   Rubber hoses and tubing:"+ANSI_BOLD+(w1*12) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*12);
+                       }
+                       if(weightsMap.containsKey("Rubberised fibres and textiles")){
+                        w1=weightsMap.get("Rubberised fibres and textiles");
+                        System.out.println("   Rubberised fibres and textiles:"+ANSI_BOLD+(w1*17) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*17);
+                       }
+                       if(weightsMap.containsKey("Thermocol")){
+                        w1=weightsMap.get("Thermocol");
+                        System.out.println("   Thermocol:"+ANSI_BOLD+(w1*19) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*19);
+                       }
+                       if(weightsMap.containsKey("Styrofoam")){
+                        w1=weightsMap.get("Styrofoam");
+                        System.out.println("   Styrofoam:"+ANSI_BOLD+(w1*15) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*15);
+                       }
+                       if(weightsMap.containsKey("Aluminium cans")){
+                        w1=weightsMap.get("Aluminium cans");
+                        System.out.println("   Aluminium cans:"+ANSI_BOLD+(w1*75) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*75);
+                       }
+                       if(weightsMap.containsKey("Clear Glass bottles")){
+                        w1=weightsMap.get("Clear Glass bottles");
+                        System.out.println("   Clear Glass bottles:"+ANSI_BOLD+(w1*7) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*7);
+                       }
+                       if(weightsMap.containsKey("Colored Glass bottles")){
+                        w1=weightsMap.get("Colored Glass bottles");
+                        System.out.println("   Colored Glass bottles:"+ANSI_BOLD+(w1*5) +" Rs/-"+ANSI_RESET);
+                        cost+=(w1*5);
+                       }
+                      
+                       System.out.println(ANSI_BOLD+"  The approximate amount that you will get in return of your total waste is:" + cost+"Rs/-"+ANSI_RESET);
+                       
+
+                    }
+                    
+                }
+                System.out.println();
+                System.out.print("  Enter the area:");
+                String uadd=sc.next();
+                String date;
+                System.out.print("  Enter your preferred date of appointment(DD/MM/YY):");
+                date=sc.next();
+                
+                
+    
+            Vol assignedVolunteer = volunteerQueueManager.assignVolunteer(uadd,date);
+        
+        if (assignedVolunteer!=null) {
+            System.out.println("  You are assigned to volunteer: "+ANSI_BOLD +assignedVolunteer.getVolname()+ANSI_RESET);
+        } else {
+            System.out.println("  No volunteer available for your residential area.");
+        }
+       
+                
+            
+            
+    
+        sc.close();
+  System.out.println("\nNever let your waste go to waste because");
+  System.out.println(ANSI_BOLD+"We have got Cash for your Trash"+ANSI_RESET);
+     }
+     
+    }// Close the Scanner object
+    }
+
+
+    private static void loadUsers() {
+        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(USER_DATA_FILE))) {
+            users = (List<User>) ois.readObject();
+        } catch (IOException | ClassNotFoundException e) {
+            // If file does not exist or cannot be read, continue with an empty list of users
+        }
+    }
+
+    private static void saveUsers() {
+        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(USER_DATA_FILE))) {
+            oos.writeObject(users);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private static boolean usernameExists(String username) {
+        for (User user : users) {
+            if (user.getUsername().equals(username)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+   // @SuppressWarnings("unused")
+    private static boolean loginUser(Scanner scanner, String username ) {
+        System.out.print("  Enter your password: ");
+        String password = scanner.nextLine();
+       
+
+        for (User user : users) {
+            if (user.getUsername().equals(username) && user.getPassword().equals(password)) {
+                System.out.println(ANSI_BOLD+"  Login successful. Welcome back, " + username + "!"+ANSI_RESET);
+                return true;
+            }
+        }
+        System.out.println("  Invalid username or password."+ANSI_BOLD+" Please try again."+ANSI_RESET);
+        return false;
+    }
+
+   // @SuppressWarnings("unchecked")
+    private static void loadVol() {
+        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(VOL_DATA_FILE))) {
+           vol = (List<Vol>) ois.readObject();
+        } catch (IOException | ClassNotFoundException e) {
+            // If file does not exist or cannot be read, continue with an empty list of users
+        }
+    }
+
+    private static void saveVol() {
+        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(VOL_DATA_FILE))) {
+            oos.writeObject(vol);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private static boolean volExists(String volname) {
+        for (Vol user : vol) {
+            if (user.getVolname().equals(volname)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static boolean loginVol(Scanner scanner, String volname) {
+        System.out.print("Enter your password: ");
+        String vol_password = scanner.nextLine();
+
+        for (Vol user : vol) {
+            if (user.getVolname().equals(volname) && user.getVPassword().equals(vol_password)) {
+                System.out.println(ANSI_BOLD+"  Login successful. Welcome back, " + volname + "!"+ANSI_RESET);
+                return true;
+            }
+        }
+        System.out.println("  Invalid username or password."+ANSI_BOLD+" Please try again."+ANSI_RESET);
+        return false;
+    }
+    
+}
+
+
+ class VolunteerQueueManager implements Serializable {
+    private static final long serialVersionUID = 1L;
+    private static final String VOLUNTEER_QUEUE_DATA_FILE = "volunteer_queues.dat";
+    private Map<String, Queue<Vol>> volunteerQueues;
+    private Map<String, Queue<Vol>> assignedVolunteers;
+
+    public VolunteerQueueManager() {
+        volunteerQueues = new HashMap<>();
+        assignedVolunteers = new HashMap<>();
+        loadVolunteerQueues();
+    }
+
+    public void addVolunteer(Vol volunteer) {
+        List<String> preferredAreas = volunteer.getPreferredAreas();
+        for (String area : preferredAreas) {
+            volunteerQueues.putIfAbsent(area, new LinkedList<>());
+            volunteerQueues.get(area).offer(volunteer);
+        }
+        saveVolunteerQueues();
+    }
+     
+
+    public Vol assignVolunteer(String userResidentialArea,String date) {
+        Queue<Vol> queue = volunteerQueues.get(userResidentialArea);
+        //System.out.println("  User's residential area: " + userResidentialArea);
+    
+        if (queue != null && !queue.isEmpty()) {
+            Queue<Vol> assignedQueue = assignedVolunteers.getOrDefault(userResidentialArea, new LinkedList<>());
+            Vol assignedVolunteer = null;
+    
+            // Ensure that a different volunteer is assigned each time
+            while (!queue.isEmpty()) {
+                Vol volunteer = queue.poll();
+                if (!assignedQueue.contains(volunteer)) {
+                    assignedVolunteer = volunteer;
+                    assignedQueue.offer(assignedVolunteer);
+                    assignedVolunteers.put(userResidentialArea, assignedQueue); // Update assigned volunteers map
+                    System.out.println("  Your waste will be collected on the date:" + date);
+                    break;
+                }
+            }
+            saveVolunteerQueues(); // Save the updated queues
+            return assignedVolunteer;
+        }
+          
+        return null;
+    }
+    
+
+    private void loadVolunteerQueues() {
+        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(VOLUNTEER_QUEUE_DATA_FILE))) {
+            volunteerQueues = (Map<String, Queue<Vol>>) ois.readObject();
+        } catch (IOException | ClassNotFoundException e) {
+            // If file does not exist or cannot be read, continue with empty queues
+        }
+    }
+
+    private void saveVolunteerQueues() {
+        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(VOLUNTEER_QUEUE_DATA_FILE))) {
+            oos.writeObject(volunteerQueues);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
+
+
+
+    
+
+    
+
+