Initial commit for 4.3

src/main/java/_4/_3/Comparable.java

@@ -0,0 +1,11 @@
+package _4._3;
+
+public interface Comparable {
+	/**
+	 * Compared this and other
+	 * Returns -1 if this less than other,
+	 *          0 if this equal to other,
+	 *          1 if this greater than other
+	 */
+	int compareTo(Comparable other);
+}

src/main/java/_4/_3/ComparableInteger.java

@@ -0,0 +1,24 @@
+package _4._3;
+
+public class ComparableInteger extends Integer implements Comparable {
+	public ComparableInteger(int value) {
+		super(value);
+	}
+
+	/**
+	 * Compared this and other
+	 * Returns -1 if this  < other,
+	 *          0 if this == other,
+	 *          1 if this  > other
+	 *
+	 * @throws NullPointerException if other == null
+	 * @throws ClassCastException   if !(other instanceof Integer)
+	 * @see Comparable#compareTo(Comparable)
+	 */
+	@Override
+	public int compareTo(Comparable other) {
+		int o = ((Integer) other).value;
+		int t = this.value;
+		return t < o ? -1 : t == o ? 0 : 1;
+	}
+}

src/main/java/_4/_3/Integer.java

@@ -0,0 +1,13 @@
+package _4._3;
+
+public class Integer {
+	protected int value;
+
+	public Integer(int value) {
+		this.value = value;
+	}
+
+	public int getValue() {
+		return this.value;
+	}
+}

src/main/java/_4/_3/Utils.java

@@ -0,0 +1,20 @@
+package _4._3;
+
+public class Utils {
+	/**
+	 * Returns the smallest element
+	 *
+	 * @throws NullPointerException           if elements == null
+	 * @throws ArrayIndexOutOfBoundsException if elements.length == 0
+	 */
+	public static Comparable getMinimum(Comparable[] elements) throws NullPointerException, IndexOutOfBoundsException {
+		Comparable min = elements[0]; // assume the first element is the smallest
+		for(int i = 1; i < elements.length; i++) {
+			Comparable candidate = elements[i];
+			if(min.compareTo(candidate) > 0) {
+				min = candidate;
+			}
+		}
+		return min;
+	}
+}