Finish the implementation of SimpleBoundedList so that it satisifies the specifi

Question

Finish the implementation of SimpleBoundedList so that it satisifies the specification

public class SimpleBoundedList<K extends Comparable<K>,V> implements List<K, V> {

   protected Object[] values;

   private int start = 0;
   private int nextEmpty = 0;

   /**
   *
   */
   public SimpleBoundedList(int bound) {
       values = new Object[bound];
   }

   @Override
   public boolean add(K key, V value) {
       boolean modify = false;
       int nextIndex = nextEmpty;

       if (((nextEmpty + 1) % values.length) != start) {
           nextEmpty = (nextEmpty + 1) % values.length;
           modify = true;
       } else if (values[nextEmpty] == null) {
           modify = true;
       }
      
       if (modify)
           values[nextIndex] = new Entry<K,V>(key,value);
      
       return modify;
   }

   @Override
   public V remove(K key) {
       // TODO Auto-generated method stub
       return null;
   }

   @SuppressWarnings("unchecked")
   @Override
   public V lookup(K key) {
       return null;
   }

   @Override
   public V remove(int n) {
       // TODO Auto-generated method stub
       return null;
   }

   @Override
   public int size() {
       return 0;
   }

   @Override
   public V get(int n) {
       return null;
   }

   @Override
   public V remove() {
       // TODO Auto-generated method stub
       return null;
   }
  
   private class Entry<K, V> {
      
       protected K key;
       protected V value;
      
       public Entry(K key, V value) {
           this.key = key;
           this.value = value;
       }

   }

}

Explanation / Answer

Hi,

Please see below the implementation of SimpleBoundedList.

Thanks.

SimpleBoundedList.java

public class SimpleBoundedList<K extends Comparable<K>,V> implements List<K, V> {
protected Object[] values;
private int start = 0;
private int nextEmpty = 0;
/**
*
*/
public SimpleBoundedList(int bound) {
values = new Object[bound];
}
/**
* To add and antry with a key and value
* @param key
* @param value
* @return
*/
public boolean add(K key, V value) {
boolean modify = false;
int nextIndex = nextEmpty;
if (((nextEmpty + 1) % values.length) != start) {
nextEmpty = (nextEmpty + 1) % values.length;
modify = true;
} else if (values[nextEmpty] == null) {
modify = true;
}
  
if (modify)
values[nextIndex] = new Entry<K,V>(key,value);
  
return modify;
}
/**
* to remove an entry with a key
* @param key
* @return
*/
public V remove(K key) {
   V deletedV = null;
   for (int i = 0; i < values.length; i++) {
   if (((Entry<K, V>) values[i]).key.compareTo(key) == 0) {
   if (values[start] == values[i]
   && values[start] != values[nextEmpty]) {
   start = (start + 1) % values.length;
   } else if (values[nextEmpty] == values[i]
   && values[start] != values[nextEmpty]) {
   nextEmpty = (nextEmpty - 1) % values.length;
   }
   deletedV = ((Entry<K,V>) values[i]).value;
   values[i] = null;
   }
   shiftList();
   }
   return deletedV;
}
/**
* To shift
*/
private void shiftList() {
Object[] tempList = new Object[values.length];

for(int i = 0; i < values.length; i++) {
if(tempList[i] != null) {
tempList[i] = values[i];
}else {
values[i] = values[(i) % values.length];
}

}
}
  
/**
* To lookup for an entry with a key
* @param key
* @return
*/
public V lookup(K key) {
   V value = null;
   for (int i = 0; i < values.length; i++) {
   if (((Entry<K, V>) values[i]).key.compareTo(key) == 0) {
   value = ((Entry<K,V>) values[i]).value;
   }
   }
   return value;
}
  
/**
* To remove an entry at index
* @param n
* @return
*/
public V remove(int n) {
   V deletedV = (V) values[n];
   values[(start + n) % values.length] = null;

   if (values[start] == null && start != nextEmpty) {
   start = (start + 1) % values.length;
   } else if (values[nextEmpty] == null && start != nextEmpty) {
   nextEmpty = (nextEmpty - 1) % values.length;
   }
   shiftList();

   return deletedV;
}
  
/**
* To get the list size
* @return
*/
public int size() {
   return Math.abs(start - nextEmpty) + 1;
}
/**
* To get an entry at index n
* @param n
* @return
*/
public V get(int n) {
   return ((Entry<K, V>) values[(start + n) % values.length]).value;
}
  
/**
* To remove na entry fromthe list
* @return
*/
public V remove() {
   V deletedV = (V) values[(start) % values.length];
   values[(start) % values.length] = null;

   if(start != nextEmpty) {
   start = (start + 1) % values.length;
   }

   shiftList();

   return deletedV;
}
  
  
/**
* Class Entry
* @author
*
* @param <K>
* @param <V>
*/
private class Entry<K, V> {
  
protected K key;
protected V value;
  
public Entry(K key, V value) {
this.key = key;
this.value = value;
}
}

}

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