#!/usr/bin/newlisp
#
# Pascal's triangle:
#	http://en.wikipedia.org/wiki/Pascal's_triangle
#
# Nov 6, 2005 - PvE.
# Revised for newLisp 10 at december 28, 2008 - PvE.
#---------------------------------------------------------------

# Calculate faculty of number using recursion
(define (fac n) (if (> n 1) (mul n (fac (- n 1))) n))

# Intro
(println "\nThis program shows Pascal's Triangle.")
(println "\nIf the results do not fit on your screen, redirect")
(println "to a file, for example: newlisp pascal.lsp > results.txt")
(print "\nHow many lines of the triangle must be calculated? ")

(set 'lines (int (read-line)))
(println)

# Define some constants
(constant 'reslen (sqrt lines))
(constant 'tabspace (* 2 reslen))

# Main routine
(for (row 0 lines)
    # Goto starting print position
    (dotimes (x (- lines row)) (print (dup " " reslen)))
    # Calculate values and print
    (for (position 0 row)
	(set 'quotient (mul (fac position) (fac (- row position)) ) )
	    (if (= quotient 0)
		(set 'result 1)
		(set 'result (div (fac row) quotient) )
	    )
	(print result (dup " " (- tabspace (length (string result)))  ))
    )
    # Next line
    (print "\n")
)
# Exit newLisp
(exit)