/*
 *  Copyright (C) 2009  E.Albert, P.Arenas, S.Genaim, G.Puebla, and D.Zanardini
 *                      https://costa.ls.fi.upm.es
 *
 *  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/>.
 */
package pubs;
/**
 * A simple class with a method doSum which adds up the factorial
 * of all naturals from 0 to the input value n.
 * 
 * @author E.Albert, P.Arenas, S.Genaim, and G.Puebla
 *
 */
public class FactSum {

	static int factorial(int n) {
		if (n <=0) return 1;
		else return n*factorial(n-1);    
	}

	static int doSum(int n){
		int s=0;
		while (n >= 0) {
			s = s + factorial(n);
			n=n-1;
		}
		return s;
	}

	public static void main(String[] args) {

		// First test
		int test = 10;
		int result = doSum(test);
		System.out.println("Result: "+result);

		/*// Second test
		test = 50;
		result = doSum(test);
		System.out.println("Result: "+result);

		// Third test
		test = 100;
		result = doSum(test);
		System.out.println("Result: "+result);
		*/
	}
}