P1-P5: rewrite to match current syllabus

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

P1.java

@@ -1,8 +1,92 @@
-class P1 {
+class Stack {
-  public static void main(String[] _args) {
+    private int[] array;
-      int a = 44;
+    private int top;
-      int b = 56;
     
-      System.out.println(a + " + " + b + " = " + (a + b));
+    public Stack(int capacity) {
-  }
+        array = new int[capacity];
+        top = -1;
+    }
+    
+    public void push(int item) {
+        if (top == array.length - 1) {
+            System.out.println("Stack Overflow");
+        } else {
+            array[++top] = item;
+            System.out.println("Pushed " + item + " to the stack");
+        }
+    }
+    
+    public int pop() {
+        if (top == -1) {
+            System.out.println("Stack Underflow");
+            return -1;
+        } else {
+            int item = array[top--];
+            System.out.println("Popped " + item + " from the stack");
+            return item;
+        }
+    }
+    
+    public boolean isEmpty() {
+        return top == -1;
+    }
+}
+
+class Queue {
+    private int[] array;
+    private int front;
+    private int rear;
+    private int size;
+    
+    public Queue(int capacity) {
+        array = new int[capacity];
+        front = 0;
+        rear = -1;
+        size = 0;
+    }
+    
+    public void enqueue(int item) {
+        if (size == array.length) {
+            System.out.println("Queue is full");
+        } else {
+            rear = (rear + 1) % array.length;
+            array[rear] = item;
+            size++;
+            System.out.println("Enqueued " + item + " to the queue");
+        }
+    }
+    
+    public int dequeue() {
+        if (size == 0) {
+            System.out.println("Queue is empty");
+            return -1;
+        } else {
+            int item = array[front];
+            front = (front + 1) % array.length;
+            size--;
+            System.out.println("Dequeued " + item + " from the queue");
+            return item;
+        }
+    }
+    
+    public boolean isEmpty() {
+        return size == 0;
+    }
+}
+
+public class P1 {
+    public static void main(String[] args) {
+        Stack stack = new Stack(5);
+        stack.push(1);
+        stack.push(2);
+        stack.pop();
+        stack.pop();
+        stack.pop();
+        
+        Queue queue = new Queue(5);
+        queue.enqueue(1);
+        queue.enqueue(-4);
+        queue.dequeue();
+        queue.dequeue();
+    }
 }

P2.java

@@ -1,11 +1,15 @@
-class P2 {
+import java.util.StringTokenizer;
-  public static void main(String[] _args) {
-      int a = 5, b, f;
-      b = f = a;
 
-      while (b-- > 1)
+public class P2 {
-          f *= b;
+    public static void main(String[] args) {
+        String input = "Hello, I am Batu Khan and I am about to blow.";
         
-      System.out.println(a + "! = " + f);
+        StringTokenizer tokenizer = new StringTokenizer(input, " ,");
-  }
+
+        int i = 0;
+        while (tokenizer.hasMoreTokens()) {
+            String token = tokenizer.nextToken();
+            System.out.println("Token " + ++i + ": " + token);
+        }
+    }
 }

P3.java

@@ -1,14 +1,27 @@
-class P3 {
+interface Animal {
-  public static void main(String[] _args) {
+    void makeSound();
-      int a = 5, b = -5, c = 55, mx;
+}
-
+
-      if (a > b && a > c)
+class Cat implements Animal {
-          mx = a;
+    @Override
-      else if ( b > a && b > c)
+    public void makeSound() {
-          mx = b;
+        System.out.println("Meow!");
-      else
+    }
-          mx = c;
+}
-
+
-      System.out.println("max(" + a + ", " + b + ", " + c + ") = " + mx);
+class Cow implements Animal {
-  }
+    @Override
+    public void makeSound() {
+        System.out.println("Moo!");
+    }
+}
+
+public class P3 {
+    public static void main(String[] args) {
+        Animal cat = new Cat();
+        Animal cow = new Cow();
+        
+        cat.makeSound();
+        cow.makeSound();
+    }
 }

P4.java

@@ -1,15 +1,57 @@
-class P4 {
+class ProducerConsumer {
-  public static void main(String[] _args) {
+    private int limit = 5;
-      int n = 10;
+    private int tmp = 0;
-      int a = 0, b = 1;
+    private int n = 0;
-      System.out.println("First " + n + " elements of the fibonacci series:");
+    private int m = 0;
-      new P4().fibo(n, a, b);
-  }
     
-    void fibo(int n, int a, int b) {
+
-        if (n == 0)
+    public void produce() throws InterruptedException {
-            return;
+        int value = 0;
-        System.out.println(a);
+        while (n++ < limit * 2) {
-        fibo(n - 1, b, a + b);
+            synchronized (this) {
+                while (tmp == limit) {
+                    wait();
+                }
+                System.out.println("Producer produced: " + tmp++);
+                notify();
+            }
+        }
+    }
+
+    public void consume() throws InterruptedException {
+        while (m++ < limit * 2) {
+            synchronized (this) {
+                while (tmp == 0) {
+                    wait();
+                }
+                System.out.println("Consumer consumed: " + --tmp);
+                notify();
+            }
+        }
+    }
+}
+
+public class P4 {
+    public static void main(String[] args) {
+        ProducerConsumer pc = new ProducerConsumer();
+
+        Thread producerThread = new Thread(() -> {
+            try {
+                pc.produce();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        });
+
+        Thread consumerThread = new Thread(() -> {
+            try {
+                pc.consume();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        });
+
+        producerThread.start();
+        consumerThread.start();
     }
 }

P5.java

@@ -1,20 +1,27 @@
-import java.util.function.Consumer;
+class MyException extends Exception {
-
+    public MyException(String message) {
-class P5 {
+        super(message);
-  public static void main(String[] _args) {
+    }
-      int sub[] = { 64, 91, 45 };
+}
-      P5 obj = new P5();
+
-      int sum = 0;
+public class P5 {
-
+    public static void main(String[] args) {
-      for (int i = 0; i < sub.length; i++) {
+        try {
-          obj.grade(sub[i], i + 1);
+            int result = divide(10, 0);
-          sum += sub[i];
+            System.out.println("Result: " + result);
-      }
+        } catch (MyException e) {
-
+            System.out.println("My Exception: " + e.getMessage());
-      System.out.println("Overall Percentage: " + (float) sum / 3 + "%");
+        } catch (ArithmeticException e) {
-  }
+            System.out.println("Arithmetic Exception: " + e.getMessage());
-
+        } finally {
-    void grade(int n, int s) {
+            System.out.println("Finally block executed.");
-        System.out.println( "Subject " + s + " grade: " +  (char)( n >= 90 ? 'A' : n < 50 ? 'F' : 'A' + (9 - n / 10)));
+        }
+    }
+
+    public static int divide(int num1, int num2) throws MyException {
+        if (num2 == 0) {
+            throw new MyException("Division by zero not allowed.");
+        }
+        return num1 / num2;
     }
 }

file.org

@@ -1,155 +0,0 @@
-#+LATEX_CLASS_OPTIONS: [a4paper,12pt]
-#+LATEX_HEADER: \usepackage[margin=0.5in]{geometry}
-#+LATEX_HEADER: \usepackage{fontspec}
-#+LATEX_HEADER: \setmainfont{LiberationSerif}
-#+LATEX_HEADER: \date{}
-#+OPTIONS: toc:nil
-
-|------------------------------------------------------------------------------------------------------------|
-| Programs are followed by their respective inputs and outputs i.e, both stdin and stdout are shown together |
-|------------------------------------------------------------------------------------------------------------|
-
-* Sum of two numbers
-#+ATTR_LATEX: :options frame=single,breaklines=true
-#+begin_src java :tangle P1.java :results output :exports both :wrap src text
-class P1 {
-  public static void main(String[] _args) {
-      int a = 44;
-      int b = 56;
-
-      System.out.println(a + " + " + b + " = " + (a + b));
-  }
-}
-#+end_src
-
-Output:
-#+RESULTS:
-#+begin_src text
-44 + 56 = 100
-#+end_src
-
-#+latex: \clearpage
-
-* Factorial of a number
-#+ATTR_LATEX: :options frame=single,breaklines=true
-#+begin_src java :tangle P2.java :results output :exports both :wrap src text
-class P2 {
-  public static void main(String[] _args) {
-      int a = 5, b, f;
-      b = f = a;
-
-      while (b-- > 1)
-          f *= b;
-
-      System.out.println(a + "! = " + f);
-  }
-}
-#+end_src
-
-Output:
-#+RESULTS:
-#+begin_src text
-5! = 120
-#+end_src
-
-#+latex: \clearpage
-
-* Greatest of 3 numbers
-#+ATTR_LATEX: :options frame=single,breaklines=true
-#+begin_src java :tangle P3.java :results output :exports both :wrap src text
-class P3 {
-  public static void main(String[] _args) {
-      int a = 5, b = -5, c = 55, mx;
-
-      if (a > b && a > c)
-          mx = a;
-      else if ( b > a && b > c)
-          mx = b;
-      else
-          mx = c;
-
-      System.out.println("max(" + a + ", " + b + ", " + c + ") = " + mx);
-  }
-}
-#+end_src
-
-Output:
-#+RESULTS:
-#+begin_src text
-max(5, -5, 55) = 55
-#+end_src
-
-#+latex: \clearpage
-
-* Fibbonaci series
-#+ATTR_LATEX: :options frame=single,breaklines=true
-#+begin_src java :tangle P4.java :results output :exports both :wrap src text
-class P4 {
-  public static void main(String[] _args) {
-      int n = 10;
-      int a = 0, b = 1;
-      System.out.println("First " + n + " elements of the fibonacci series:");
-      new P4().fibo(n, a, b);
-  }
-
-    void fibo(int n, int a, int b) {
-        if (n == 0)
-            return;
-        System.out.println(a);
-        fibo(n - 1, b, a + b);
-    }
-}
-#+end_src
-
-max(5, -5, 55) = 55
-#+RESULTS:
-#+begin_src text
-First 10 elements of the fibonacci series:
-0
-1
-1
-2
-3
-5
-8
-13
-21
-34
-#+end_src
-
-#+latex: \clearpage
-
-* Percentage marks and grades for 3 subjects
-#+ATTR_LATEX: :options frame=single,breaklines=true
-#+begin_src java :tangle P5.java :results output :exports both :wrap src text
-import java.util.function.Consumer;
-
-class P5 {
-  public static void main(String[] _args) {
-      int sub[] = { 64, 91, 45 };
-      P5 obj = new P5();
-      int sum = 0;
-
-      for (int i = 0; i < sub.length; i++) {
-          obj.grade(sub[i], i + 1);
-          sum += sub[i];
-      }
-
-      System.out.println("Overall Percentage: " + (float) sum / 3 + "%");
-  }
-
-    void grade(int n, int s) {
-        System.out.println( "Subject " + s + " grade: " +  (char)( n >= 90 ? 'A' : n < 50 ? 'F' : 'A' + (9 - n / 10)));
-    }
-}
-#+end_src
-
-#+RESULTS:
-#+begin_src text
-Subject 1 grade: D
-Subject 2 grade: A
-Subject 3 grade: F
-Overall Percentage: 66.666664%
-#+end_src
-
-#+latex: \clearpage