Return an implementation of a Comparable
/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
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.Calendar;
import java.util.GregorianCalendar;
/**
* @version 1.00 2004-05-10
* @author Cay Horstmann
*/
public class PairTest2
{
public static void main(String[] args)
{
GregorianCalendar[] birthdays =
{
new GregorianCalendar(1906, Calendar.DECEMBER, 9), // G. Hopper
new GregorianCalendar(1815, Calendar.DECEMBER, 10), // A. Lovelace
new GregorianCalendar(1903, Calendar.DECEMBER, 3), // J. von Neumann
new GregorianCalendar(1910, Calendar.JUNE, 22), // K. Zuse
};
Pair<GregorianCalendar> mm = ArrayAlg.minmax(birthdays);
System.out.println("min = " + mm.getFirst().getTime());
System.out.println("max = " + mm.getSecond().getTime());
}
}
class ArrayAlg
{
/**
Gets the minimum and maximum of an array of objects of type T.
@param a an array of objects of type T
@return a pair with the min and max value, or null if a is
null or empty
*/
public static <T extends Comparable> Pair<T> minmax(T[] a)
{
if (a == null || a.length == 0) return null;
T min = a[0];
T max = a[0];
for (int i = 1; i < a.length; i++)
{
if (min.compareTo(a[i]) > 0) min = a[i];
if (max.compareTo(a[i]) < 0) max = a[i];
}
return new Pair<T>(min, max);
}
}
/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
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/>.
*/
/**
* @version 1.00 2004-05-10
* @author Cay Horstmann
*/
class Pair<T>
{
public Pair() { first = null; second = null; }
public Pair(T first, T second) { this.first = first; this.second = second; }
public T getFirst() { return first; }
public T getSecond() { return second; }
public void setFirst(T newValue) { first = newValue; }
public void setSecond(T newValue) { second = newValue; }
private T first;
private T second;
}
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