MODULE fact2;
(*---------------------------------------------------------
File name: fact2.pm
Author: AG, MM
Date: 5/19/05 

Problem: This program calculates factorial sequentially. A 
PROCEDURE is defined which does the operations, main calls
the procedure. Procedure uses a WHILE loop to calculate factorial.
	No configuration is defined, everything is calculated 
	trought the controller

Example of Execution:
	Enter N?: 5
	N! = 120
	
Cycles:
N multiplications + N additions. 
*)
(*----------------------------------------------------------
		VARIABLES
----------------------------------------------------------*)
VAR 
		N, F: INTEGER;
(*----------------------------------------------------------
		PROCEDURES
----------------------------------------------------------*)
PROCEDURE Fact(N: INTEGER);
(*----------------------------------------------------------
		PROCEDURE VARIABLES
----------------------------------------------------------*)
VAR
		K: INTEGER;
(*----------------------------------------------------------
		PROCEDURE MAIN
----------------------------------------------------------*)
BEGIN
	F:=1;
	K:=1;
	WHILE K <= N DO
		F:= F*K;
		K:= K + 1;
	END; (*FOR *)
END Fact;   (* Result is in Global variable F *)
(*----------------------------------------------------------
		MAIN
----------------------------------------------------------*)
BEGIN
	(*Reading *)
	WriteString("Enter N?: "); ReadInt(N); (* Read N *)
	
	(* call function *)
	Fact(N);
	
	(*printing*)
	WriteString("  N! = " ); WriteInt(F, 2);
END fact2.