Find all sets of three numbers with a given number

/**
 * FindAllSetsOfThreeNumbersWithAGivenSum.java
 * 
 * Description: Given an array with integers and a number n, design an
algorithm
 * and write code to print all pairs of numbers that sum to this number.
 * 
 * FOLLOW UP: Find all sets of THREE nubmers that summed to this value.
 * 
 * @author John Qiao <qiaoshun8888@gmail.com> Date: Jan 26, 2014
 */