shuffle.h

/*******************************************************************************
 * DANIEL'S ALGORITHM IMPLEMENTAIONS
 *
 *  /\  |  _   _  ._ o _|_ |_  ._ _   _ 
 * /--\ | (_| (_) |  |  |_ | | | | | _> 
 *         _|                      
 *
 * FISHER YATES'S SHUFFLE 
 *
 * Features:
 * 1. shuffle list in O(n) time.
 *
 * http://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle
 * 
 ******************************************************************************/

#ifndef ALGO_SHUFFLE_H__
#define ALGO_SHUFFLE_H__

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

namespace alg {
	/**
	 * shuffle the 'list' of length 'len'
	 */
	template<typename T>
		static void shuffle(T * list, int len) {
			srand(time(NULL));
			int i = len, j;
			T temp;

			if ( i == 0 ) return;
			while ( --i ) {
				j = rand() % (i+1);
				temp = list[i];
				list[i] = list[j];
				list[j] = temp;
			}
		}
}

#endif //