tasks a-s

2013-04-10 23:57:08 -07:00 · 2013-04-10 23:57:08 -07:00 · b83f433714
commit b83f433714
parent 47bf37c096
12433 changed files with 156208 additions and 123 deletions
--- a/Task/N-queens-problem/PicoLisp/n-queens-problem-2.l
+++ b/Task/N-queens-problem/PicoLisp/n-queens-problem-2.l
@ -0,0 +1,16 @@
+(de queens (N)
+   (let (R (range 1 N)  L (copy R)  X L  Cnt 0)
+      (recur (X)  # Permute
+         (if (cdr X)
+            (do (length X)
+               (recurse (cdr X))
+               (rot X) )
+            (or
+               (seek  # Direct check for duplicates
+                  '((L) (member (car L) (cdr L)))
+                  (mapcar + L R) )
+               (seek
+                  '((L) (member (car L) (cdr L)))
+                  (mapcar - L R) )
+               (inc 'Cnt) ) ) )
+      Cnt ) )