From 0b0e20baf82563de4e2b3735baeafbc7c14d6b15 Mon Sep 17 00:00:00 2001
From: Giovanni Di Grezia <xgiovio@gmail.com>
Date: Sun, 18 May 2014 16:47:04 +0200
Subject: [PATCH] Ordered List e BinarySearchTree

---
 com/xgiovio/OrderedListSetTest.java |  51 ++++++++
 dictionary/BinarySearchTree.java    | 180 ++++++++++++++++++++++++++++
 set/OrderedListSet.java             |  53 +++++---
 utility/merge/MergeTemplate.java    |  46 +++++--
 4 files changed, 300 insertions(+), 30 deletions(-)
 create mode 100644 com/xgiovio/OrderedListSetTest.java
 create mode 100644 dictionary/BinarySearchTree.java

diff --git a/com/xgiovio/OrderedListSetTest.java b/com/xgiovio/OrderedListSetTest.java
new file mode 100644
index 0000000..ab17e4e
--- /dev/null
+++ b/com/xgiovio/OrderedListSetTest.java
@@ -0,0 +1,51 @@
+package com.xgiovio;
+
+import position.NodePositionList;
+import set.OrderedListSet;
+
+import java.security.InvalidKeyException;
+
+/**
+ * Created with MONSTER.
+ * User: xgiovio
+ * Date: 18/05/2014
+ * Time: 15:58
+ */
+public class OrderedListSetTest {
+
+    public static void main(String[] args) {
+
+        NodePositionList<String> t = new NodePositionList<String>();
+        t.addLast("1");
+        t.addLast("2");
+        t.addLast("5");
+        t.addLast("6");
+        t.addLast("8");
+        OrderedListSet<String> a = new OrderedListSet<String>(t);
+        System.out.println(a);
+
+
+        NodePositionList<String> t2 = new NodePositionList<String>();
+        t2.addLast("3");
+        t2.addLast("4");
+        t2.addLast("5");
+        t2.addLast("7");
+        t2.addLast("8");
+        t2.addLast("9");
+        t2.addLast("12");
+        OrderedListSet<String> a2 = new OrderedListSet<String>(t2);
+        System.out.println(a2);
+
+        a.subtract(a2);
+        System.out.println(a);
+
+
+
+
+
+
+
+
+
+    }
+}
diff --git a/dictionary/BinarySearchTree.java b/dictionary/BinarySearchTree.java
new file mode 100644
index 0000000..727e15c
--- /dev/null
+++ b/dictionary/BinarySearchTree.java
@@ -0,0 +1,180 @@
+package dictionary;
+import exceptions.InvalidEntryException;
+import position.NodePositionList;
+import position.Position;
+import position.PositionList;
+import priorityqueue.Entry;
+import tree.binarytree.BTPosition;
+import tree.binarytree.LinkedBinaryTree;
+import utility.DefaultComparator;
+
+import java.security.InvalidKeyException;
+import java.util.Comparator;
+
+
+
+
+public class BinarySearchTree<K,V>   extends LinkedBinaryTree<Entry<K,V>> implements Dictionary<K,V> {
+
+  protected Comparator<K> C;	// comparator
+  protected Position<Entry<K,V>>  actionPos; // insert node or removed node's parent
+  protected int numEntries = 0;	// number of entries
+
+  public BinarySearchTree()  { 
+    C = new DefaultComparator<K>();
+    addRoot(null);
+  }
+
+  public BinarySearchTree(Comparator<K> c)  { 
+    C = c; 
+    addRoot(null);
+  }
+
+  /** Nested class for location-aware binary search tree entries */
+  protected static class BSTEntry<K,V> implements Entry<K,V> {
+    protected K key;
+    protected V value;
+    protected Position<Entry<K,V>> pos;
+    BSTEntry(K k, V v, Position<Entry<K,V>> p) { 
+      key = k; value = v; pos = p;
+    }
+    public K getKey() { return key; }
+    public V getValue() { return value; }
+    public Position<Entry<K,V>> position() { return pos; }
+  }
+
+  /** Extracts the key of the entry at a given node of the tree. */
+  protected K key(Position<Entry<K,V>> position)  {
+    return position.element().getKey();
+  }
+
+  /** Extracts the value of the entry at a given node of the tree. */  
+  protected V value(Position<Entry<K,V>> position)  { 
+    return position.element().getValue(); 
+  }
+
+  /** Extracts the entry at a given node of the tree. */  
+  protected Entry<K,V> entry(Position<Entry<K,V>> position)  { 
+    return position.element();
+  }
+
+  /** Replaces an entry with a new entry (and reset the entry's location) */
+  protected void replaceEntry(Position <Entry<K,V>> pos, Entry<K,V> ent) {
+    ((BSTEntry<K,V>) ent).pos = pos;
+    replace(pos, ent);
+  }
+
+
+protected void checkKey(K key) throws InvalidKeyException {
+  if(key == null)
+    throw new InvalidKeyException("null key");
+}
+
+protected void checkEntry(Entry<K,V> ent) throws InvalidEntryException {
+  if(ent == null || !(ent instanceof BSTEntry))
+    throw new InvalidEntryException("invalid entry");
+}
+
+protected Entry<K,V> insertAtExternal(Position<Entry<K,V>> v, Entry<K,V> e) {
+  expandExternal(v,null,null);
+  replace(v, e);
+  numEntries++;
+  return e;
+}
+/** Auxiliary method for removing an external node and its parent */
+protected void removeExternal(Position<Entry<K,V>> v) {
+  removeAboveExternal(v);
+  numEntries--;
+}
+/** Auxiliary method used by find, insert, and remove. */
+protected Position<Entry<K,V>> treeSearch(K key, Position<Entry<K,V>> pos) {
+  if (isExternal(pos)) return pos; // key not found; return external node
+  else {
+    K curKey = key(pos);
+    int comp = C.compare(key, curKey);
+    if (comp < 0) 
+      return treeSearch(key, left(pos));	// search left subtree
+    else if (comp > 0)
+      return treeSearch(key, right(pos));	// search right subtree
+    return pos;		// return internal node where key is found
+  }
+}
+
+
+// Adds to L all entries in the subtree rooted at v having keys equal to k
+protected void addAll(PositionList<Entry<K,V>> L, Position<Entry<K,V>> v, K k) {
+  if (isExternal(v)) return;
+  Position<Entry<K,V>> pos = treeSearch(k, v);
+  if (!isExternal(pos))  {  // we found an entry with key equal to k 
+    addAll(L, left(pos), k);
+    L.addLast(pos.element()); 	// add entries in inorder
+    addAll(L, right(pos), k);
+  } // this recursive algorithm is simple, but it's not the fastest
+}
+
+  /** Returns the number of entries in the tree. */
+  public int size() { return numEntries; }
+
+  /** Returns whether the tree is empty. */
+  public boolean isEmpty() { return size() == 0; }
+
+  /** Returns an entry containing the given key.  Returns null if no such entry exists. */
+  public Entry<K,V> find(K key) throws InvalidKeyException {
+    checkKey(key);		// may throw an InvalidKeyException
+    Position<Entry<K,V>> curPos = treeSearch(key, root());
+    actionPos = curPos;		// node where the search ended
+    if (isInternal(curPos)) return entry(curPos);
+    return null;
+  }
+
+  /** Returns an iterable collection of all the entries containing the  given key. */
+  public Iterable<Entry<K,V>> findAll(K key) throws InvalidKeyException {
+    checkKey(key);		// may throw an InvalidKeyException
+    PositionList<Entry<K,V>> L = new NodePositionList<Entry<K,V>>();
+    addAll(L, root(), key);
+    return L;
+  }
+
+  /** Inserts an entry into the tree and returns the newly created entry. */
+  public Entry<K,V> insert(K k, V x) throws InvalidKeyException {
+    checkKey(k);	// may throw an InvalidKeyException
+    Position<Entry<K,V>> insPos = treeSearch(k, root());
+    while (!isExternal(insPos))  // iterative search for insertion position
+      insPos = treeSearch(k, left(insPos));
+    actionPos = insPos;	// node where the new entry is being inserted
+    return insertAtExternal(insPos, new BSTEntry<K,V>(k, x, insPos));
+  }
+
+  /** Removes and returns a given entry. */
+  public Entry<K,V> remove(Entry<K,V> ent) throws InvalidEntryException  {
+    checkEntry(ent);            // may throw an InvalidEntryException
+    Position<Entry<K,V>> remPos = ((BSTEntry<K,V>) ent).position(); 
+    Entry<K,V> toReturn = entry(remPos);	// entry to be returned
+    if (isExternal(left(remPos))) remPos = left(remPos);  // left easy case
+    else if (isExternal(right(remPos))) remPos = right(remPos); // right easy case
+    else {			//  entry is at a node with internal children
+      Position<Entry<K,V>> swapPos = remPos;	// find node for moving entry
+      remPos = right(swapPos);
+      do
+	    remPos = left(remPos);
+      while (isInternal(remPos));
+      replaceEntry(swapPos, (Entry<K,V>) parent(remPos).element());
+    }
+    actionPos = sibling(remPos);	// sibling of the leaf to be removed
+    removeExternal(remPos);
+    return toReturn;
+  }
+
+  /** Returns an iterator containing all entries in the tree. */
+  public Iterable<Entry<K,V>> entries() {
+    PositionList<Entry<K,V>> entries = new NodePositionList<Entry<K,V>>();
+    Iterable<Position<Entry<K,V>>> positer = positions();
+    for (Position<Entry<K,V>> cur: positer)
+      if (isInternal(cur))
+	entries.addLast(cur.element());
+    return entries;
+  }
+
+
+}
+
diff --git a/set/OrderedListSet.java b/set/OrderedListSet.java
index e20f1a3..9db9606 100644
--- a/set/OrderedListSet.java
+++ b/set/OrderedListSet.java
@@ -20,16 +20,26 @@ public class OrderedListSet <E> implements Set<E> {
 
 
 
-    OrderedListSet() {
+    public OrderedListSet() {
         L = new NodePositionList<E>();
-        c = new DefaultComparator();
+        c = new DefaultComparator<E>();
     }
 
-    OrderedListSet(Comparator<E> in_c) {
+    public OrderedListSet(Comparator<E> in_c) {
         L = new NodePositionList<E>();
         c = in_c;
     }
 
+    public OrderedListSet(PositionList<E> in_l){
+        L = in_l;
+        c = new DefaultComparator<E>();
+    }
+
+    public OrderedListSet(PositionList<E> in_l,Comparator<E> in_c ){
+        L = in_l;
+        c = in_c;
+    }
+
 
 
 
@@ -47,50 +57,59 @@ public class OrderedListSet <E> implements Set<E> {
 
 
     @Override
-    public Set<E> union(Set<E> B) {return null;
+    public Set<E> union(Set<E> B) {
+        MergeUnion<E> ret = new MergeUnion<E>(L, ((OrderedListSet<E>)B).L , c );
+        L = ret.getResult();
+        return this;
+
     }
 
     @Override
     public Set<E> intersect(Set<E> B) {
-        return null;
+        MergeIntersect<E> ret = new MergeIntersect<E>(L, ((OrderedListSet<E>)B).L , c );
+        L = ret.getResult();
+        return this;
     }
 
     @Override
     public Set<E> subtract(Set<E> B) {
-        return null;
+        MergeSubtract<E> ret = new MergeSubtract<E>(L, ((OrderedListSet<E>)B).L , c );
+        L = ret.getResult();
+        return this;
     }
 
-
-
-
+    @Override
+    public String toString() {
+        return L.toString();
+    }
 
     //////////////////////// inner class override methods from merge template /////
 
     protected class MergeUnion<E> extends MergeTemplate<E>{
 
-           public MergeUnion (PositionList<E> A , PositionList<E> B, DefaultComparator<E> c){
+           public MergeUnion (PositionList<E> A , PositionList<E> B, Comparator<E> c){
                  super(A,B,c);
            }
 
            @Override
            protected void aIsLess(E a) {
-
+                  s.addLast(a);
            }
 
            @Override
            protected void bIsLess(E b) {
-
+                    s.addLast(b);
            }
 
            @Override
            protected void bothAreEqual(E a, E b) {
-
+                    s.addLast(a);
            }
        }
 
     protected class MergeIntersect<E> extends MergeTemplate<E>{
 
-        public MergeIntersect (PositionList<E> A , PositionList<E> B, DefaultComparator<E> c){
+        public MergeIntersect (PositionList<E> A , PositionList<E> B, Comparator<E> c){
             super(A,B,c);
         }
 
@@ -106,19 +125,19 @@ public class OrderedListSet <E> implements Set<E> {
 
         @Override
         protected void bothAreEqual(E a, E b) {
-
+            s.addLast(a);
         }
     }
 
     protected class MergeSubtract<E> extends MergeTemplate<E>{
 
-        public MergeSubtract (PositionList<E> A , PositionList<E> B, DefaultComparator<E> c){
+        public MergeSubtract (PositionList<E> A , PositionList<E> B, Comparator<E> c){
             super(A,B,c);
         }
 
         @Override
         protected void aIsLess(E a) {
-
+            s.addLast(a);
         }
 
         @Override
diff --git a/utility/merge/MergeTemplate.java b/utility/merge/MergeTemplate.java
index 64f298a..654ac5c 100644
--- a/utility/merge/MergeTemplate.java
+++ b/utility/merge/MergeTemplate.java
@@ -19,8 +19,8 @@ import java.util.Iterator;
  */
 public abstract class MergeTemplate<E> {
 
-    PositionList<E> s = new NodePositionList<E>();
-    Comparator<E> c = null;
+    protected PositionList<E> s = new NodePositionList<E>();
+    protected Comparator<E> c = null;
 
     public MergeTemplate (PositionList<E> A, PositionList <E> B){
             this(A,B,new DefaultComparator<E>());
@@ -29,29 +29,49 @@ public abstract class MergeTemplate<E> {
     public MergeTemplate (PositionList<E> A, PositionList <E> B, Comparator<E> in_c){
 
         c = in_c;
-        E a,b;
+        E a = null ,b = null;
         Iterator<E> Ait, Bit;
         Ait = A.iterator();
         Bit = B.iterator();
 
-        while (!(Ait.hasNext()) && !(Bit.hasNext())) {
 
+        if ( Ait.hasNext() && Bit.hasNext() ){
             a = Ait.next();
-            b= Bit.next();
+            b = Bit.next();
+            for (; true; ) {
 
-            if ( c.compare(a,b) < 0 )
-                aIsLess(a);
-            else if (c.compare(a,b) > 0)
-                bIsLess(b);
-                else // se b = a
-            bothAreEqual(a, b);
+                if (c.compare(a, b) < 0) {
+                    aIsLess(a);
+                    if (Ait.hasNext())
+                        a = Ait.next();
+                    else
+                        break;
+                } else {
+                    if (c.compare(a, b) > 0) {
+                        bIsLess(b);
+                        if (Bit.hasNext())
+                            b = Bit.next();
+                        else
+                            break;
 
+                    } else {// se b = a
+                        bothAreEqual(a, b);
+                        if (Ait.hasNext() && Bit.hasNext()) {
+                            a = Ait.next();
+                            b = Bit.next();
+                        } else
+                            break;
+
+                    }
+                }
+
+            }
         }
-        while (!(Ait.hasNext())) {
+        while ( Ait.hasNext() ) {
             a = Ait.next();
             aIsLess(a);
         }
-        while (!(Bit.hasNext())) {
+        while ( Bit.hasNext()) {
             b = Bit.next();
             bIsLess(b);
         }