diff --git a/1ano/2semestre/poo/guides/POO-2022-aula10.pdf b/1ano/2semestre/poo/guides/POO-2022-aula10.pdf
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Binary files /dev/null and b/1ano/2semestre/poo/guides/POO-2022-aula10.pdf differ
diff --git a/1ano/2semestre/poo/src/aula10/ex1/Book.java b/1ano/2semestre/poo/src/aula10/ex1/Book.java
new file mode 100644
index 0000000..49f16d3
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula10/ex1/Book.java
@@ -0,0 +1,39 @@
+package aula10.ex1;
+
+import java.util.Objects;
+
+public class Book {
+    private String title;
+    private String author;
+    private int year;
+
+    public Book(String title, String author, int year) {
+        this.setTitle(title);
+        this.setAuthor(author);
+        this.setYear(year);
+    }
+
+    public String getTitle() { return this.title; }
+    public void setTitle(String title) { this.title = title; }
+    public String getAuthor() { return this.author; }
+    public void setAuthor(String author) { this.author = author; }
+    public int getYear() { return this.year; }
+    public void setYear(int year) { this.year = year; }
+
+    @Override
+    public String toString() {
+        return String.format("%s, %s, %d", this.getTitle(), this.getAuthor(), this.getYear());
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Book book)) return false;
+        return getYear() == book.getYear() && Objects.equals(getTitle(), book.getTitle()) && Objects.equals(getAuthor(), book.getAuthor());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(getTitle(), getAuthor(), getYear());
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula10/ex1/BooksTest.java b/1ano/2semestre/poo/src/aula10/ex1/BooksTest.java
new file mode 100644
index 0000000..36a0b12
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula10/ex1/BooksTest.java
@@ -0,0 +1,30 @@
+package aula10.ex1;
+
+import java.util.HashMap;
+
+public class BooksTest {
+    static HashMap<String, Book> books = new HashMap<>() {
+        @Override
+        public String toString() {
+            StringBuilder sb = new StringBuilder();
+            for (String genre : this.keySet()) {
+                sb.append(genre).append(" : ").append(this.get(genre)).append("\n");
+            }
+            return sb.toString();
+        }
+    };
+
+    public static void main(String[] args) {
+        books.put("Fantasia", new Book("Harry Potter", "J. K. Rowling", 1997));
+        books.put("Ficção Científica", new Book("The Martian", "Andy Weir", 2011));
+        books.put("Romance", new Book("Pride and Prejudice", "Jane Austen", 1813));
+        books.put("Terror", new Book("The Shining", "Stephen King", 1977));
+        System.out.println(books);
+        for (String genre : books.keySet()) {
+            System.out.println(genre);
+        }
+        for (Book book : books.values()) {
+            System.out.println(book);
+        }
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula10/ex2/BooksTest.java b/1ano/2semestre/poo/src/aula10/ex2/BooksTest.java
new file mode 100644
index 0000000..8dc7519
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula10/ex2/BooksTest.java
@@ -0,0 +1,44 @@
+package aula10.ex2;
+
+import aula10.ex1.Book;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+
+public class BooksTest {
+    static HashMap<String, LinkedList<Book>> books = new HashMap<>() {
+        @Override
+        public String toString() {
+            StringBuilder sb = new StringBuilder();
+            for (String genre : this.keySet()) {
+                sb.append(genre).append(":");
+                for (Book book : this.get(genre)) {
+                    sb.append("\n\t").append(book);
+                }
+                sb.append("\n");
+            }
+            return sb.toString();
+        }
+    };
+
+    public static void main(String[] args) {
+        books.put("Fantasia", new LinkedList<>());
+        books.put("Ficção Científica", new LinkedList<>());
+        books.put("Romance", new LinkedList<>());
+        books.put("Terror", new LinkedList<>());
+        books.get("Fantasia").add(new Book("Harry Potter", "J. K. Rowling", 1997));
+        books.get("Ficção Científica").add(new Book("The Martian", "Andy Weir", 2011));
+        books.get("Romance").add(new Book("Pride and Prejudice", "Jane Austen", 1813));
+        books.get("Terror").add(new Book("The Shining", "Stephen King", 1977));
+        books.get("Fantasia").add(new Book("The Hobbit", "J. R. R. Tolkien", 1937));
+        books.get("Ficção Científica").add(new Book("The Hitchhiker's Guide to the Galaxy", "Douglas Adams", 1979));
+        books.get("Romance").add(new Book("Jane Eyre", "Charlotte Brontë", 1847));
+        books.get("Terror").add(new Book("Frankenstein", "Mary Shelley", 1818));
+        System.out.println(books);
+        System.out.print(selectRandomBook("Fantasia"));
+    }
+
+    public static Book selectRandomBook(String genre) {
+        return books.get(genre).get((int) (Math.random() * books.get(genre).size()));
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula10/ex3/CharacterCounter.java b/1ano/2semestre/poo/src/aula10/ex3/CharacterCounter.java
new file mode 100644
index 0000000..854cc88
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula10/ex3/CharacterCounter.java
@@ -0,0 +1,45 @@
+package aula10.ex3;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+
+public class CharacterCounter {
+    private final HashMap<Character, Integer> counter = new HashMap<>();
+    private final HashMap<Character, LinkedList<Integer>> indexes = new HashMap<>();
+    private final String text;
+
+    public CharacterCounter(String text) {
+        this.text = text;
+    }
+
+    public void count() {
+        for (char c : this.text.toCharArray()) {
+            if (this.counter.containsKey(c)) {
+                this.counter.put(c, this.counter.get(c) + 1);
+            } else {
+                this.counter.put(c, 1);
+            }
+        }
+    }
+
+    public void indexes() {
+        for (int i = 0; i < this.text.length(); i++) {
+            char c = this.text.charAt(i);
+            if (this.indexes.containsKey(c)) {
+                this.indexes.get(c).add(i);
+            } else {
+                LinkedList<Integer> list = new LinkedList<>();
+                list.add(i);
+                this.indexes.put(c, list);
+            }
+        }
+    }
+
+    public HashMap<Character, Integer> getCounter() {
+        return this.counter;
+    }
+
+    public HashMap<Character, LinkedList<Integer>> getIndexes() {
+        return this.indexes;
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula10/ex3/Main.java b/1ano/2semestre/poo/src/aula10/ex3/Main.java
new file mode 100644
index 0000000..0dd8795
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula10/ex3/Main.java
@@ -0,0 +1,11 @@
+package aula10.ex3;
+
+public class Main {
+    public static void main(String[] args) {
+        CharacterCounter counter = new CharacterCounter("Hello World!");
+        counter.count();
+        System.out.println(counter.getCounter());
+        counter.indexes();
+        System.out.println(counter.getIndexes());
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula10/ex4/FileReaderTest.java b/1ano/2semestre/poo/src/aula10/ex4/FileReaderTest.java
new file mode 100644
index 0000000..ac5ef6d
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula10/ex4/FileReaderTest.java
@@ -0,0 +1,29 @@
+package aula10.ex4;
+
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.util.LinkedList;
+import java.util.Scanner;
+
+public class FileReaderTest {
+    public static void main(String[] args) {
+        LinkedList<String> words = new LinkedList<>();
+        Scanner input;
+        try {
+            input = new Scanner(new FileReader("src/aula10/ex4/words.txt"));
+        } catch (FileNotFoundException e) {
+            throw new RuntimeException(e);
+        }
+        while(input.hasNext()){
+            String word = input.next();
+            if (word.length() > 2) {
+                words.add(word);
+            }
+            System.out.println(word);
+        }
+        for (String word : words)
+            if (word.endsWith("s"))
+                System.out.println(word);
+        words.removeIf(word -> !word.matches("^[a-zA-Záàãâéẽêíóõôúç]+$"));
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula10/ex4/words.txt b/1ano/2semestre/poo/src/aula10/ex4/words.txt
new file mode 100644
index 0000000..290bd17
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula10/ex4/words.txt
@@ -0,0 +1,2 @@
+Testing the file reader with some simple and random text.
+Should also have words ended with s
\ No newline at end of file