add dictionary stuff

java/Dictionary/Dictionary.java

@@ -0,0 +1,28 @@
+/** The Dictionary abstract class */
+public interface Dictionary<Key, E> {
+
+  /** Reinitialize dictionary */
+  public void clear();
+
+  /** Insert a record.
+   * @param k The key for the record being inserted.
+   * @param e The record being inserted. */
+  public void insert(Key k, E e);
+
+  /** Remove and return a record.
+   * @param k The key of the record to be removed.
+   * @return A matching record. If multiple records match "k", remove an arbitrary one. Return null if no record with key "k" exists. */
+  public E remove(Key k);
+
+  /** Remove and return arbitrary record from dictionary.
+   * @return the record removed, or null if none exists. */
+  public E removeAny();
+
+  /** @return A record matching "k" (null if none exists).
+   * If multiple records match, return an arbitrary one. 
+   * @param k The key of the record to find */
+  public E find(Key k);
+
+  /** @return The number of records in the dictionary. */
+  public int size();
+};

java/Dictionary/KVpair.java

@@ -0,0 +1,24 @@
+/** Container class for a key-value pair */
+class KVpair<Key, E> {
+	private Key k;
+	private E e;
+
+	/** Constructors */
+	KVpair() {
+		k = null;
+		e = null;
+	}
+
+	KVpair(Key kval, E eval) {
+		k = kval; e = eval;
+	}
+
+	/** Data member access functions */
+	public Key key() {
+		return k;
+	}
+
+	public E value() {
+		return e;
+	}
+}

java/Dictionary/Payroll.java

@@ -0,0 +1,18 @@
+/** A simple payroll entry with ID, name, address fields */
+class Payroll {
+	private Integer ID;
+	private String name;
+	private String address;
+
+	/** Constructor */
+	Payroll(int inID, String inname, String inaddr) {
+		id = inID;
+		name = inname;
+		address = inaddr;
+	}
+
+  /** Data member access functions */
+  public Integer getID() { return ID; }
+  public String getname() { return name; }
+  public String getaddr() { return address; }
+}

java/Dictionary/UALdictionary.java

@@ -0,0 +1,59 @@
+/** Dictionary implemented by unsorted array-based list */
+class UALdictionary<Key, E> implements Dictionary<Key, E> {
+	private static final int defaultSize = 10;	// Default size
+	private AList<KVpair<Key, E>> list;	// To store dictionary
+	
+	/** Constructors */
+	UALdictionary() {
+		this(defaultSize);
+	}
+
+	UALdictionary(int sz) {
+		list = new AList<KVpair<Key, E>>(sz);
+	}
+
+	/** Reintialize */
+	public void clear() {
+		list.clear();
+	}
+
+	/** Insert an element: append to list */
+	public void insert(Key k, E e) {
+		KVpair<Key, E> temp = new KVpair<Key, E>(k , e);
+		list.append(temp);
+	}
+
+	/** Use sequential search to find the element to remove */
+	public E remove(Key k) {
+		E temp = find(k);
+		if (temp != null) list.remove();
+		return temp;
+	}
+
+	/** Remove the last element */
+	public E removeAny() {
+		if (size != 0) {
+			list.moveToEnd();
+			list.prev();
+			KVpair<Key, E> e = list.remove();
+
+			return e.value();
+		}
+		else return null;
+	}
+
+	/** Find k using sequential search 
+	 * @return Record with key value k */
+	public E find(Key k) {
+		for (list.moveToStart(); list.curPos() < list.length(); list.next()) {
+			KVpair<Key, E> temp = list.getValue();
+			if (k == temp.key()) return temp.value();
+		}
+		return null;	// "k" does not appear in dictionary
+	}
+
+	/** @return List size */
+	public int size() {
+		return list.length();
+	}
+}