How to print a list as matrix in Common Lisp

Question

I am working in Common Lisp, trying to make Windows game minesweeper.

I have a list (1 1 1 2 2 2 3 3 3) and want to print that like matrix

(1 1 1
2 2 2
3 3 3)

How to do that?

Edit

I am at the beginning of

(format t "Input width:")
(setf width (read)) 
(format t "Input height:")
(setf height (read))    
(format t "How many mines:")
(setf brMina (read))

(defun matrica (i j)
  (cond ((= 0 i) '())
    (t  (append (vrsta j) (matrica  (1- i) j) ))))


(setf minefield (matrica width height))

(defun stampaj ()
      (format t "~%~a" minefield ))

Answer 1

Another example, using the pretty-printer for fun:

(defun print-list-as-matrix
    (list elements-per-row
     &optional (cell-width (1+ (truncate (log (apply #'max list) 10)))))
  (let ((*print-right-margin* (* elements-per-row (1+ cell-width)))
        (*print-miser-width* nil)
        (*print-pretty* t)
        (format-string (format nil "~~<~~@{~~~ad~~^ ~~}~~@:>~%" cell-width)))
    (format t format-string list)))

Works like this:

CL-USER> (print-list-as-matrix (loop for i from 1 to 9 collect i) 3)
1 2 3
4 5 6
7 8 9
NIL
CL-USER> (print-list-as-matrix (loop for i from 1 to 25 collect i) 5)
 1  2  3  4  5
 6  7  8  9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
NIL
CL-USER> (print-list-as-matrix (loop for i from 1 to 16 collect i) 2)
 1  2
 3  4
 5  6
 7  8
 9 10
11 12
13 14
15 16

Answer 2

Like this:

(defun print-list-as-grid (list rows cols)
  (assert (= (length list) (* rows cols))
  (loop for row from 0 below rows do
     (loop for col from 0 below cols do
        (princ (car list))
        (princ #\space)
        (setf list (cdr list)))
     (princ #\newline)))

* (print-list-as-grid '(a b c d e f g h i) 3 3)
A B C 
D E F 
G H I 

NIL