/* Lecture code 10.0
 *
 * Demonstrating the boost::lambda library along with BOOST_FOREACH on an array of numbers.
 * Note that this code will only work if you have the Boost libraries installed on your system.
 */
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <boost/foreach.hpp> // For BOOST_FOREACH
#include <boost/lambda/lambda.hpp> // For _1, _2.
using namespace std;
using namespace boost::lambda;

/* This next line simplifies the use of BOOST_FOREACH by letting us just
 * write foreach instead.
 */
#define foreach BOOST_FOREACH

const int NUM_INTS = 24;

int main()
{
	/* Seed the randomizer.  Consult a reference for more info. */
	srand((unsigned int)time(NULL));
	
	int myArray[NUM_INTS];
	
	/* Use generate to populate the array with random numbers. */
	generate(myArray, myArray + NUM_INTS, rand);
	
	/* Sort the numbers in reverse order.  The final parameter is a lambda expression
	 * which returns true if the first integer is greater than the second.
	 */
	sort(myArray, myArray + NUM_INTS, _2 < _1);
	
	/* Transform the numbers by replacing each with its square, minus 137. */
	transform(myArray, myArray + NUM_INTS, myArray, (_1 * _1) - 137);
	
	/* Print out the array using foreach. */
	foreach(int n, myArray)
		cout << n << endl;
	
	return 0;
}