Yurttas/PL/OOL/Cplusplus/F/02/04/022/00/01/factorial.cpp

 1/*
 2   Copyright(C) 1998
 3   All Rights Reserved. Salih Yurttas, ZCubes, BitsOfCode Software Systems, Inc..
 4
 5   Permission to use, copy, modify, and distribute this
 6   software and its documentation for EDUCATIONAL purposes
 7   and without fee is hereby granted provided that this
 8   copyright notice appears in all copies.
 9
10   date   : January 1, 1998.
11   author : Salih Yurttas.
12
13   factorial.cpp
14*/
15
16
17long factorial(long n) {
18  if(n<0) return -1;
19  else if(n==0) return 1;
20
21  long a = 1;
22
23  for(int i=1; i<=n; ++i)
24    a *= i;
25
26  return a;
27}