inital commit

Lab106-VenbergGE/src/LuckyNumberList.java

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+/*
+ * Copyright (C) 2021 Gabriel Venberg
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import java.util.NoSuchElementException;
+
+/**
+ *
+ * @author Gabriel Venberg
+ */
+public class LuckyNumberList {
+    private LinkedPositionalList<LuckyNumber> luckyNumbers;
+    
+    public LuckyNumberList(){
+        luckyNumbers = new LinkedPositionalList<LuckyNumber>();
+    }
+    
+    public void addLuckyNumber(LuckyNumber l){
+        luckyNumbers.addLast(l);
+    }
+    
+    private class positionIterator implements Iterator<Position<LuckyNumber>>{
+        private Position<LuckyNumber> cursor = luckyNumbers.first();
+        private Position<LuckyNumber> recent = null;
+        
+        public boolean hasNext(){return(cursor!=null);}
+        
+        public Position<LuckyNumber> next() throws NoSuchElementException {
+            if(cursor==null){throw new NoSuchElementException("nothing left");}
+            recent = cursor;
+            cursor = luckyNumbers.after(cursor);
+            return recent;
+        }
+        public void remove() throws IllegalStateException{
+            if(recent==null){throw new IllegalStateException("nothing to remove");}
+            luckyNumbers.remove(recent);
+            recent=null;
+        }
+    }
+    
+    private class positionIterable implements Iterable<Position<LuckyNumber>>{
+        public Iterator<Position<LuckyNumber>> iterator(){return new positionIterator();}
+    }
+    
+    public Iterable<Position<LuckyNumber>> positions(){
+        return new positionIterable();
+    }
+    
+    private class EvenPositionIterator implements Iterator<Position<LuckyNumber>>{
+        private Position<LuckyNumber> cursor = luckyNumbers.first();
+        private Position<LuckyNumber> recent = null;
+        
+        public boolean hasNext(){return(cursor!=null);}
+        
+        public Position<LuckyNumber> next() throws NoSuchElementException {
+            if(cursor==null){throw new NoSuchElementException("nothing left");}
+            if(recent==null){
+                while((cursor != null) && !(cursor.getElement().getLuckyNumber()%2==0)){
+                    cursor = luckyNumbers.after(cursor);
+                }
+            }
+            recent = cursor;
+            cursor = luckyNumbers.after(cursor);
+            //advance cursor to next even number
+            while((cursor != null) && !(cursor.getElement().getLuckyNumber()%2==0)){
+                cursor = luckyNumbers.after(cursor);
+            }
+         return recent;
+        }
+        public void remove() throws IllegalStateException{
+            if(recent==null){throw new IllegalStateException("nothing to remove");}
+            luckyNumbers.remove(recent);
+            recent=null;
+        }
+    }
+    
+    private class EvenPositionIterable implements Iterable<Position<LuckyNumber>>{
+        public Iterator<Position<LuckyNumber>> iterator(){return new EvenPositionIterator();}
+    }
+    
+    public Iterable<Position<LuckyNumber>> EvenPositions(){
+        return new EvenPositionIterable();
+    }
+    
+    //utility class
+    private boolean isPrime(int n){
+        for(int i=2; i<n/2;i++){
+            if(n%i==0){return false;}
+        }
+        return true;
+    }
+    
+    private class PrimePositionIterator implements Iterator<Position<LuckyNumber>>{
+        private Position<LuckyNumber> cursor = luckyNumbers.first();
+        private Position<LuckyNumber> recent = null;
+        
+        public boolean hasNext(){return(cursor!=null);}
+        
+        public Position<LuckyNumber> next() throws NoSuchElementException {
+            if(cursor==null){throw new NoSuchElementException("nothing left");}
+            if(recent==null){
+                while(cursor != null && !isPrime(cursor.getElement().getLuckyNumber())){
+                    cursor = luckyNumbers.after(cursor);
+                }
+            }
+            recent = cursor;
+            cursor = luckyNumbers.after(cursor);
+            //advance cursor to next even number
+            while(cursor != null && !isPrime(cursor.getElement().getLuckyNumber())){
+                cursor = luckyNumbers.after(cursor);
+            }
+         return recent;
+        }
+        public void remove() throws IllegalStateException{
+            if(recent==null){throw new IllegalStateException("nothing to remove");}
+            luckyNumbers.remove(recent);
+            recent=null;
+        }
+    }
+    
+    private class PrimePositionIterable implements Iterable<Position<LuckyNumber>>{
+        public Iterator<Position<LuckyNumber>> iterator(){return new PrimePositionIterator();}
+    }
+    
+    public Iterable<Position<LuckyNumber>> PrimePositions(){
+        return new PrimePositionIterable();
+    }
+    
+    
+}