Einführung in die objektorientierte Programmierung

Aufg1

class Entry<ET>{
  ET element;
  Entry<ET> next; 
  Entry<ET> previous; 
  
  Entry(ET elem){
    this.element = elem;
  }
}


class Queue<ET>{
  
  Entry<ET> first;
  
  int size;
  
  Queue(int anzahl){
    size=anzahl;
    if (size==0) {
      first=null;
    } 
    else {
      Entry<ET> zeiger=null;
      first=new Entry<ET>(null);
      Entry<ET> alt= first;
      for (int i=1; i<size; i++ ) {
        zeiger= new Entry<ET>(null);
        alt.next=zeiger;
        zeiger.previous=alt;
        alt=zeiger;
      } // end of for
      zeiger.next= first;
      first.previous= zeiger;
    } // end of if-else
  }
  
  public void insert(ET wert){
    first = first.next;
    first.element=wert;
  }
  
  public void print(){
    Entry<ET> zeiger=first;
    for (int i=1;i<=size ;i++ ) { 
      if (zeiger.element != null) {       
        System.out.println(String.valueOf( zeiger.element));      
      }
      zeiger= zeiger.previous;
    } // end of while
  }
  
  
  public static void main(String[] args){
    Queue<Object> q= new Queue<Object>(4);
    
    q.insert(new String("1"));
    q.insert(new String("2"));
    q.insert(new String("3"));
    //   q.insert(new String("4"));
    // q.insert(new String("5"));
    // q.insert(new String("6"));
    
    q.print();
  }
  
}

Aufg3

import java.util.*;

class Morse{
   LinkedList<String> morsealphabet = new LinkedList<String>();
   
   Morse(){
   morsealphabet.addLast(".-");
   morsealphabet.addLast("-...");
   morsealphabet.addLast("-.-.");
   morsealphabet.addLast("-..");
   morsealphabet.addLast(".");
   morsealphabet.addLast("..-.");
   }
   
   public String code(char b) throws NoSuchElementException{
   int index= ((int) b) - 65;
   //return morsealphabet.get(((int) b) - 65); 
   //  return (index >=0 && index<=5) ? 
   //  morsealphabet.get(((int) b) - 65): "Fehler!"; 
   if (index >=0 && index<=5) {
   return morsealphabet.get(((int) b) - 65);
   } // end of if
   else {
   throw new NoSuchElementException();
   } // end of if-else
   
   }
   
   public static void main(String[] args){
   Morse uebersetzer = new Morse();
   String wort= args[0];
   for (int i=0; i<wort.length() ;i++ ) {
   try{
   System.out.println( uebersetzer.code(wort.charAt(i)) );
   }
   catch (NoSuchElementException e) {
   System.out.println("Geschafft");
   }
   } // end of for
   }
   }

Aufg5

class BinaryNode {
  private BinaryNode leftSon, rightSon;
  private int value;
  public BinaryNode(int i) {
    leftSon = rightSon = null;
    value = i;
  }
  public boolean contains(int v) { 
    if (v<this.value) {
      if (this.leftSon==null) {
        return false;
      } // end of if
      else{
        return this.leftSon.contains(v);
      }
    } // end of if
    if(v>this.value){
      if (this.rightSon==null) {
        return false;
      } // end of if
      else{
        return this.rightSon.contains(v);
      }
    } // end of if-else
    return true;
  }
  
  public void insert(int v) {  
    if (v<this.value) {
      if (this.leftSon==null) {
        this.leftSon = new BinaryNode(v);
      } // end of if
      else {
        this.leftSon.insert(v);
      } // end of if-else
    } // end of if
    else if (v>this.value) {
      if (this.rightSon==null) {
        this.rightSon = new BinaryNode(v);
      } // end of if
      else {
        this.rightSon.insert(v);
      } // end of if-else
    } // end of if
  }
  
  
  public void inorder() { 
    if (this.leftSon != null) {
      this.leftSon.inorder();
    } // end of if
    System.out.println(this.value);
    if (this.rightSon != null) {
      this.rightSon.inorder();
    } // end of if
  }
  
}



public class TestTree {
  public static void main(String[] args) {
    BinaryNode myTree = new BinaryNode(6);
    myTree.insert(5);
    myTree.insert(4);
    myTree.insert(12);
    myTree.insert(11);
    myTree.insert(10);
    
    myTree.inorder();
    
    System.out.println(myTree.contains(44) ); 
  }
}

Pakete

Beispiel:

In G:\fernuni_hamburg\objektor_sprachen\2017\Pakete\paketA befindet sich:

package paketA;

import paketB.*;

public class A{
   public static void main(String[] args){
   B b =new B();
   b.m(7);
   }
}

In G:\fernuni_hamburg\objektor_sprachen\2017\Pakete\paketB befindet sich:

package paketB;

public class B{
   public void m(int n){
   System.out.println(n);
   }
}

Im Class Path steht

G:\Fernuni_Hamburg\Objektor_Sprachen\2017\Pakete