Josephus Problem with cyclic iterator











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Given the Josephus Problem.




Josephus Problem



N people (numbered 1 to N) are standing in a circle. Person 1 kills Person 2 with a sword and gives it to Person 3. Person 3 kills Person 4 and gives the sword to Person 5. This process is repeated until only one person is alive.



Task:
(Medium) Given the number of people N, write a program to find the number of the person that stays alive at the end.
(Hard) Show each step of the process.



(The description from Sololearn application)"




This is my code. The forEachRemaining method solution is correct? I have to do something with this inherited method, but it has no meaning.



import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.function.Consumer;

class CyclicIterator implements Iterator {

private final List list;
private Iterator iterator;

public CyclicIterator(List list) {
this.list = list;
initIterator(list);
}

private void initIterator(List list) {
this.iterator = list.iterator();
}

@Override
public boolean hasNext() {
return !list.isEmpty();
}

@Override
public Object next() {
if (!this.iterator.hasNext())
initIterator(list);
return this.iterator.next();
}

@Override
public void remove() {
this.iterator.remove();
}

@Override
public void forEachRemaining(Consumer action) {
throw new UnsupportedOperationException("This method has no meaning in CyclicIterator class!");
}
}

public class JosephusProblem {

public static void main(String args) {
execution(0);
execution(1);
execution(2);
execution(4);
execution(6);
}

private static void execution(int members) {
if (members < 1) {
System.out.println("The parameter (members) has to be bigger than 0!");
return;
}
if (members == 1) {
System.out.println("There is olny one person, so he is the survivor. Peaceful version! :)");
return;
}
LinkedList<Integer> list = new LinkedList();
for (int index = 0; index < members; index++)
list.add(index + 1);
Iterator<Integer> it = new CyclicIterator(list);
System.out.println("For " + members + " members: ");
while (members-- > 1) {
System.out.print(it.next() + " kills " + it.next() + ", ");
it.remove();
}
System.out.println("n The survivor: " + it.next());
}


}










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    up vote
    0
    down vote

    favorite












    Given the Josephus Problem.




    Josephus Problem



    N people (numbered 1 to N) are standing in a circle. Person 1 kills Person 2 with a sword and gives it to Person 3. Person 3 kills Person 4 and gives the sword to Person 5. This process is repeated until only one person is alive.



    Task:
    (Medium) Given the number of people N, write a program to find the number of the person that stays alive at the end.
    (Hard) Show each step of the process.



    (The description from Sololearn application)"




    This is my code. The forEachRemaining method solution is correct? I have to do something with this inherited method, but it has no meaning.



    import java.util.Iterator;
    import java.util.LinkedList;
    import java.util.List;
    import java.util.function.Consumer;

    class CyclicIterator implements Iterator {

    private final List list;
    private Iterator iterator;

    public CyclicIterator(List list) {
    this.list = list;
    initIterator(list);
    }

    private void initIterator(List list) {
    this.iterator = list.iterator();
    }

    @Override
    public boolean hasNext() {
    return !list.isEmpty();
    }

    @Override
    public Object next() {
    if (!this.iterator.hasNext())
    initIterator(list);
    return this.iterator.next();
    }

    @Override
    public void remove() {
    this.iterator.remove();
    }

    @Override
    public void forEachRemaining(Consumer action) {
    throw new UnsupportedOperationException("This method has no meaning in CyclicIterator class!");
    }
    }

    public class JosephusProblem {

    public static void main(String args) {
    execution(0);
    execution(1);
    execution(2);
    execution(4);
    execution(6);
    }

    private static void execution(int members) {
    if (members < 1) {
    System.out.println("The parameter (members) has to be bigger than 0!");
    return;
    }
    if (members == 1) {
    System.out.println("There is olny one person, so he is the survivor. Peaceful version! :)");
    return;
    }
    LinkedList<Integer> list = new LinkedList();
    for (int index = 0; index < members; index++)
    list.add(index + 1);
    Iterator<Integer> it = new CyclicIterator(list);
    System.out.println("For " + members + " members: ");
    while (members-- > 1) {
    System.out.print(it.next() + " kills " + it.next() + ", ");
    it.remove();
    }
    System.out.println("n The survivor: " + it.next());
    }


    }










    share|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      Given the Josephus Problem.




      Josephus Problem



      N people (numbered 1 to N) are standing in a circle. Person 1 kills Person 2 with a sword and gives it to Person 3. Person 3 kills Person 4 and gives the sword to Person 5. This process is repeated until only one person is alive.



      Task:
      (Medium) Given the number of people N, write a program to find the number of the person that stays alive at the end.
      (Hard) Show each step of the process.



      (The description from Sololearn application)"




      This is my code. The forEachRemaining method solution is correct? I have to do something with this inherited method, but it has no meaning.



      import java.util.Iterator;
      import java.util.LinkedList;
      import java.util.List;
      import java.util.function.Consumer;

      class CyclicIterator implements Iterator {

      private final List list;
      private Iterator iterator;

      public CyclicIterator(List list) {
      this.list = list;
      initIterator(list);
      }

      private void initIterator(List list) {
      this.iterator = list.iterator();
      }

      @Override
      public boolean hasNext() {
      return !list.isEmpty();
      }

      @Override
      public Object next() {
      if (!this.iterator.hasNext())
      initIterator(list);
      return this.iterator.next();
      }

      @Override
      public void remove() {
      this.iterator.remove();
      }

      @Override
      public void forEachRemaining(Consumer action) {
      throw new UnsupportedOperationException("This method has no meaning in CyclicIterator class!");
      }
      }

      public class JosephusProblem {

      public static void main(String args) {
      execution(0);
      execution(1);
      execution(2);
      execution(4);
      execution(6);
      }

      private static void execution(int members) {
      if (members < 1) {
      System.out.println("The parameter (members) has to be bigger than 0!");
      return;
      }
      if (members == 1) {
      System.out.println("There is olny one person, so he is the survivor. Peaceful version! :)");
      return;
      }
      LinkedList<Integer> list = new LinkedList();
      for (int index = 0; index < members; index++)
      list.add(index + 1);
      Iterator<Integer> it = new CyclicIterator(list);
      System.out.println("For " + members + " members: ");
      while (members-- > 1) {
      System.out.print(it.next() + " kills " + it.next() + ", ");
      it.remove();
      }
      System.out.println("n The survivor: " + it.next());
      }


      }










      share|improve this question













      Given the Josephus Problem.




      Josephus Problem



      N people (numbered 1 to N) are standing in a circle. Person 1 kills Person 2 with a sword and gives it to Person 3. Person 3 kills Person 4 and gives the sword to Person 5. This process is repeated until only one person is alive.



      Task:
      (Medium) Given the number of people N, write a program to find the number of the person that stays alive at the end.
      (Hard) Show each step of the process.



      (The description from Sololearn application)"




      This is my code. The forEachRemaining method solution is correct? I have to do something with this inherited method, but it has no meaning.



      import java.util.Iterator;
      import java.util.LinkedList;
      import java.util.List;
      import java.util.function.Consumer;

      class CyclicIterator implements Iterator {

      private final List list;
      private Iterator iterator;

      public CyclicIterator(List list) {
      this.list = list;
      initIterator(list);
      }

      private void initIterator(List list) {
      this.iterator = list.iterator();
      }

      @Override
      public boolean hasNext() {
      return !list.isEmpty();
      }

      @Override
      public Object next() {
      if (!this.iterator.hasNext())
      initIterator(list);
      return this.iterator.next();
      }

      @Override
      public void remove() {
      this.iterator.remove();
      }

      @Override
      public void forEachRemaining(Consumer action) {
      throw new UnsupportedOperationException("This method has no meaning in CyclicIterator class!");
      }
      }

      public class JosephusProblem {

      public static void main(String args) {
      execution(0);
      execution(1);
      execution(2);
      execution(4);
      execution(6);
      }

      private static void execution(int members) {
      if (members < 1) {
      System.out.println("The parameter (members) has to be bigger than 0!");
      return;
      }
      if (members == 1) {
      System.out.println("There is olny one person, so he is the survivor. Peaceful version! :)");
      return;
      }
      LinkedList<Integer> list = new LinkedList();
      for (int index = 0; index < members; index++)
      list.add(index + 1);
      Iterator<Integer> it = new CyclicIterator(list);
      System.out.println("For " + members + " members: ");
      while (members-- > 1) {
      System.out.print(it.next() + " kills " + it.next() + ", ");
      it.remove();
      }
      System.out.println("n The survivor: " + it.next());
      }


      }







      java linked-list circular-list






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      asked Nov 14 at 13:27









      MAttti

      184




      184






















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          The documentation for forEachRemaining states that the behavior is equivalent to



          while (hasNext())
          action.accept(next());


          so why not just put that there?






          share|improve this answer








          New contributor




          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.


















          • I think that would be an infinite loop. The hasNext() is always true if the list is not empty.
            – MAttti
            2 days ago










          • Of course the next line has a next() call in it … action.accept(next()).
            – K.Nicholas
            2 days ago











          Your Answer





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          1 Answer
          1






          active

          oldest

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          1 Answer
          1






          active

          oldest

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          active

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          active

          oldest

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          up vote
          0
          down vote













          The documentation for forEachRemaining states that the behavior is equivalent to



          while (hasNext())
          action.accept(next());


          so why not just put that there?






          share|improve this answer








          New contributor




          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.


















          • I think that would be an infinite loop. The hasNext() is always true if the list is not empty.
            – MAttti
            2 days ago










          • Of course the next line has a next() call in it … action.accept(next()).
            – K.Nicholas
            2 days ago















          up vote
          0
          down vote













          The documentation for forEachRemaining states that the behavior is equivalent to



          while (hasNext())
          action.accept(next());


          so why not just put that there?






          share|improve this answer








          New contributor




          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.


















          • I think that would be an infinite loop. The hasNext() is always true if the list is not empty.
            – MAttti
            2 days ago










          • Of course the next line has a next() call in it … action.accept(next()).
            – K.Nicholas
            2 days ago













          up vote
          0
          down vote










          up vote
          0
          down vote









          The documentation for forEachRemaining states that the behavior is equivalent to



          while (hasNext())
          action.accept(next());


          so why not just put that there?






          share|improve this answer








          New contributor




          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.









          The documentation for forEachRemaining states that the behavior is equivalent to



          while (hasNext())
          action.accept(next());


          so why not just put that there?







          share|improve this answer








          New contributor




          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.









          share|improve this answer



          share|improve this answer






          New contributor




          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.









          answered Nov 15 at 5:04









          K.Nicholas

          1011




          1011




          New contributor




          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.





          New contributor





          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.






          K.Nicholas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
          Check out our Code of Conduct.












          • I think that would be an infinite loop. The hasNext() is always true if the list is not empty.
            – MAttti
            2 days ago










          • Of course the next line has a next() call in it … action.accept(next()).
            – K.Nicholas
            2 days ago


















          • I think that would be an infinite loop. The hasNext() is always true if the list is not empty.
            – MAttti
            2 days ago










          • Of course the next line has a next() call in it … action.accept(next()).
            – K.Nicholas
            2 days ago
















          I think that would be an infinite loop. The hasNext() is always true if the list is not empty.
          – MAttti
          2 days ago




          I think that would be an infinite loop. The hasNext() is always true if the list is not empty.
          – MAttti
          2 days ago












          Of course the next line has a next() call in it … action.accept(next()).
          – K.Nicholas
          2 days ago




          Of course the next line has a next() call in it … action.accept(next()).
          – K.Nicholas
          2 days ago


















           

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