#!/usr/bin/newlisp
;; Copyright (c) 2006, Sarken LLC
;; Contact: Gordon Fischer [ fischer@sarken.org ]
;; Released under the Creative Commons Attribution License
;; http://creativecommons.org/licenses/by/2.5/

(println "How many lines?")
(set 'lines (int (read-line)))

;; The following code starts at zero not one
;; http://www.turtle.dds.nl/newlisp/pascal.lsp
;; So uncomment this for comparisons
;; (inc 'lines)

;; Let's make a triangular matrix of depth lines
;; But let's not duplicate work instead of this ...
;; 1
;; 1 1
;; 1 2 1
;; 1 3 3 1
;; let's just store (because we know it's symmetric)
;; 1
;; 1
;; 1 2
;; 1 3

(println
(time (begin

(define (even? x) (= 0 (% x 2)))
(set 'tri (dup '() lines))

(define (cellval row col)
  (if (or (= col 0) (< row 2))
    (push 1 tri row col)
    (push (+ (tri (- row 1) (- col 1)) (tri (- row 1) col) ) tri row col)
))

(dotimes (x lines)
  (dotimes (y (+ 1 (floor (div x 2))))
   (cellval x y)
))

;; now we have the basis of the triangle

(set 'max-width (length (string (apply max (flat tri)))))

;; This allows us to have nice formatting
(if (even? max-width)
  (set 'cell-padding 2)
  (set 'cell-padding 3)
)
(set 'empty-cell (dup " " (+ max-width cell-padding)))

(define (print-cell x) (format (string "%" (+ max-width cell-padding) "d") x))

(dotimes (x lines)
  (set 'tmp (map print-cell (tri x)))
  (if (even? x)
    ;; If it's even we indent and add 1/2 a cell for padding.
    (println (append (dup empty-cell (ceil (div (- lines x) 2))) (0 (/ (length empty-cell) 2) empty-cell)
      ;; This line formats the values of the triangle and dupes the symmetric numbers
      (join (append tmp (reverse (chop tmp))))))
    (println (append (dup empty-cell (ceil (div (- lines x -1) 2)))
      (join (append tmp (reverse tmp)))))
  )
)

) 1) " ms")

(exit)