Week4 Tasks added

Week 4/Bonus Task/.gitignore

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+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

Week 4/Bonus Task/Bonus Task.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

Week 4/Bonus Task/src/Main.java

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+import java.util.*;
+public class Main {
+    public static void main(String[] args) {
+        StringManipulation sm = new StringManipulation();
+        StringTokenizerManipulation stm = new StringTokenizerManipulation();
+
+        Scanner scanner = new Scanner(System.in);
+        String sentence = "Hello / World, Hello /word: Hello -World ?";
+        String word = "World";
+
+        System.out.println("number of occurrences of " + word);
+        System.out.println("Using StringTokenizer Class: " + stm.wordCounts(sentence,word));
+        System.out.println("Using String Class(Method 1): " + sm.wordCounts1(sentence,word));
+        System.out.println("Using String Class(Method 1): " + sm.wordCounts2(sentence,word));
+
+
+
+        word = "Hello";
+        System.out.println("\nnumber of occurrences of " + word);
+        System.out.println("Using StringTokenizer Class: " + stm.wordCounts(sentence,word));
+        System.out.println("Using String Class(Method 1): " + sm.wordCounts1(sentence,word));
+        System.out.println("Using String Class(Method 1): " + sm.wordCounts2(sentence,word));
+
+    }
+}

Week 4/Bonus Task/src/StringManipulation.java

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+import java.util.HashMap;
+import java.util.StringTokenizer;
+public class StringManipulation {
+
+    String removeSpecialLetters(String sentence){
+        StringBuilder sb = new StringBuilder(sentence);
+        for(int i=0 ; i<sb.length();i++){
+            if(!Character.isLetter(sb.charAt(i)))
+                sb.replace(i,i+1," ");
+        }
+        return sb.toString();
+    }
+
+
+    public int wordCounts1 (String sentence, String word){
+        sentence = removeSpecialLetters(sentence);
+        String[] words = sentence.split(" ");
+        int count = 0;
+        for (String w : words) {
+            if (w.equals(word)) count++;
+        }
+        return count;
+    }
+
+    public int wordCounts2 (String sentence, String word){
+        sentence = removeSpecialLetters(sentence);
+        int count = 0;
+        int begin = 0;
+        for(int i=0;i<sentence.length();i++){
+            if(sentence.charAt(i) == ' '){
+                if(sentence.substring(begin,i).equals(word)) count++;
+                begin = i+1;
+            }
+        }
+        return count;
+    }
+}

Week 4/Bonus Task/src/StringTokenizerManipulation.java

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+import java.util.StringTokenizer;
+
+public class StringTokenizerManipulation {
+    public int wordCounts(String sentence, String word){
+        sentence = new StringManipulation().removeSpecialLetters(sentence);
+        StringTokenizer st = new StringTokenizer(sentence);
+        int count = 0;
+        while (st.hasMoreElements()) {
+            if (word.equals(st.nextToken())) count++;
+        }
+        return count;
+    }
+}

Week 4/Library System/.gitignore

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+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

Week 4/Library System/Library System.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

Week 4/Library System/src/Book.java

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+public class Book {
+    private String book_title , author_name;
+    private int book_id;
+    private double book_version;
+    private boolean isAvailable;
+
+    public Book(String book_title,String author_name,int book_id,double book_version) {
+        this.book_title = book_title;
+        this.book_id = book_id;
+        this.author_name = author_name;
+        this.book_version = book_version;
+        this.isAvailable = true;
+    }
+
+    public String getBook_title() {
+        return book_title;
+    }
+
+    public String getAuthor_name() {
+        return author_name;
+    }
+
+    public int getBook_id() {
+        return book_id;
+    }
+
+    public double getBook_version() {
+        return book_version;
+    }
+
+    public boolean isAvailable() {
+        return isAvailable;
+    }
+    public void setAvailable(boolean available){
+        this.isAvailable = available;
+    }
+}

Week 4/Library System/src/Library.java

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+import java.util.ArrayList;
+
+public class Library {
+    private String library_name;
+    private int library_code;
+    private ArrayList<Book> books = new ArrayList<>() ;
+    private ArrayList<User> users = new ArrayList<>();
+
+    public Library(String library_name,int library_code){
+        this.library_name = library_name;
+        this.library_code = library_code;
+    }
+    public void addUser(User user){
+        users.add(user);
+        System.out.println("User added successfully!");
+    }
+    public void addBook(Book book){
+        books.add(book);
+        System.out.println("Book added successfully!");
+    }
+
+    // This method removed a book from a collection of books by taking an integer parameter book_id.
+    // The method iterates through the collection of books to find the book with the matching book_id,
+    // removes it from the collection, and prints a success message. If the book_id is not found,
+    // the method prints an error message and exits the program.
+    public void removeBook(int book_id){
+        for(Book book:books){
+            if(book_id == book.getBook_id()){
+                books.remove(book);
+                System.out.println("Book removed successfully!");
+                return;
+            }
+        }
+        System.out.println("invalid book id!");
+        System.exit(0);
+    }
+
+    // This method called checkoutBook, which takes two integer arguments: user_id and book_id.
+    // The method iterates through the list of users to find the user with the specified user_id. It then checks
+    // if the book with the specified book_id is available to be borrowed. If the book is available, it is borrowed by the user,
+    // and a success message is printed to the console. If the book is not available, an error message is printed and the program exits
+    public void checkoutBook(int user_id,int book_id){
+        for(User u : users){
+            if(user_id == u.getUser_id()) {
+                for (Book book : books)
+                    if (book_id == book.getBook_id() && book.isAvailable()) {
+                        u.borrow_book(book);
+                        System.out.println("Book checked out successfully!");
+                        return;
+                    }
+               }
+           }
+
+        System.out.println("Book unavailable for check out!");
+        System.exit(0);
+    }
+
+    // This method used to return a book borrowed by a user. It takes two parameters, user_id and book_id,
+    // and searches through the collection of users to find the user with the matching user_id. It then searches through
+    // the borrowed_books list of that user to find the book with the matching book_id. If the book is found,
+    // the user's return_book() method is called to return the book and a success message is printed. If the book is not found,
+    // a "Book not found!" message is printed and the program exits.
+    public void returnBook(int user_id,int book_id){
+        for(User u : users){
+            if(user_id == u.getUser_id()){
+                for(Book book: u.getBorrowed_books()){
+                    if(book_id == book.getBook_id()){
+                        u.return_book(book);
+                        System.out.println("Book returned successfully!");
+                        return;
+                    }
+                }
+            }
+        }
+        System.out.println("Book not found!");
+        System.exit(0);
+    }
+    // This method used to display a list of available books.
+    // It iterates through a collection of Book objects, checks if each book is available by calling the isAvailable() method,
+    // and prints the titles of available books to the console.
+    public void showAvailableBooks(){
+        System.out.println("Available Books:");
+        for(Book book : books){
+            if(book.isAvailable())
+                System.out.print( "   " + book.getBook_title());
+        }
+        System.out.println();
+    }
+
+    // This method takes a userId as an argument and displays the list of books borrowed by the user with the given userId,
+    // and then iterates over a list of users to find the user with the given userId. If the user is found and has borrowed books,
+    // the method prints the list of borrowed books for that user. Otherwise, the method prints a message indicating that the user has no borrowed books.
+    // If the user is not found in the list of users, the method prints a message indicating that the user was not found and exits the program.
+    public void showBorrowedBooks(int userId){
+        for(User u: users){
+            if(userId == u.getUser_id()){
+                if(u.getBorrowed_books().size() > 0) {
+                    System.out.println("Borrowed Books of user with id = " + userId);
+                    for (Book book : u.getBorrowed_books()) {
+                        System.out.println(book.getBook_id() + " " + book.getBook_title() + '\n');
+                    }
+                } else {
+                    System.out.println("No Borrowed Books!");
+                }
+                return;
+            }
+        }
+        System.out.println("User not found!");
+        System.exit(0);
+    }
+
+    // This method takes an integer book_id as an argument and displays the details of the corresponding book if it is found in the collection of books.
+    // and then iterates through the list of books and checks if the book_id matches the id of any book in the list.
+    // If a match is found, the details of the book (such as title, author, version, and availability) are printed to the console.
+    //If the book is not found in the list, the message "Book not found!" is printed to the console, and the program exits.
+    public void showBookDetails(int book_id){
+        for(Book book : books){
+            if(book_id == book.getBook_id()){
+                System.out.println("Book Details:");
+                System.out.println("Book Id: " + book.getBook_id() + "\nBook Title:" + book.getBook_title() +
+                        "\nBook Author: " + book.getAuthor_name()
+                        + "\nBook Version: " + book.getBook_version() + "\nBook Availability:" + book.isAvailable());
+                return;
+            }
+        }
+        System.out.println("Book not found!");
+        System.exit(0);
+    }
+}