1 files changed, 58 insertions, 40 deletions
diff --git a/sudoku.scm b/sudoku.scm
index d759fa7..7b1743c 100644
--- a/sudoku.scm
+++ b/sudoku.scm
@@ -1,53 +1,71 @@
 (use-modules
+  (srfi srfi-1)
   (sat solver)
   (sat helpers))
 
 ;; Board indices: column row value
 (define board-size 9)
 
-(solve-sat
-  (let ((board (make-array #f
-                           board-size
-                           board-size
-                           board-size)))
-    (array-map! board make-sat-variable)
 
-    ;; No row contains duplicate values
-    (do ((row 0 (1+ row))) ((= row board-size))
-      (do ((value 0 (1+ value))) ((= value board-size))
-        (exactly-one-true
-          (map
-            (lambda (col)
-              (array-ref board col row value))
-            (iota board-size)))))
+(define (get-value board vals col row)
+  (1+
+   (find
+     (lambda (possible-value)
+       (array-ref vals
+                  (array-ref board col row possible-value)))
+     (iota board-size))))
+
+
+(let ((board (make-array #f
+                         board-size
+                         board-size
+                         board-size)))
+  (array-map! board make-sat-variable)
+
+  ;; No row contains duplicate values
+  (do ((row 0 (1+ row))) ((= row board-size))
+    (do ((value 0 (1+ value))) ((= value board-size))
+      (exactly-one-true
+        (map
+          (lambda (col)
+            (array-ref board col row value))
+          (iota board-size)))))
 
-    ;; No column contains duplicate values
-    (do ((col 0 (1+ col))) ((= col board-size))
+  ;; No column contains duplicate values
+  (do ((col 0 (1+ col))) ((= col board-size))
+    (do ((value 0 (1+ value))) ((= value board-size))
+      (exactly-one-true
+        (map
+          (lambda (row)
+            (array-ref board col row value))
+          (iota board-size)))))
+
+  ;; No 3x3 box contains duplicate values
+  (do ((col 0 (+ 3 col))) ((= col board-size))
+    (do ((row 0 (+ 3 row))) ((= row board-size))
       (do ((value 0 (1+ value))) ((= value board-size))
         (exactly-one-true
-          (map
-            (lambda (row)
-              (array-ref board col row value))
-            (iota board-size)))))
-
-    ;; No 3x3 box contains duplicate values
-    (do ((col 0 (+ 3 col))) ((= col board-size))
-      (do ((row 0 (+ 3 row))) ((= row board-size))
-        (do ((value 0 (1+ value))) (= value board-size)
-          (exactly-one-true
-            (let loop ((l '()))
-              (do ((col1 0 (+ 3 col1))) ((= col1 3))
-                (do ((row1 0 (+ 3 row1))) ((= row1 3))
-                  (loop (cons (array-ref board
+          (let ((l '()))
+            (do ((col1 0 (1+ col1))) ((= col1 3))
+              (do ((row1 0 (1+ row1))) ((= row1 3))
+                (set! l (cons (array-ref board
                                          (+ col col1)
-                                         (+ row row1))
-                              l)))))))))
+                                         (+ row row1)
+                                         value)
+                              l))))
+            l)))))
 
-    ;; Each position contains exactly one number
-    (do ((col 0 (1+ col))) ((= col board-size))
-      (do ((row 0 (1+ row))) ((= row board-size))
-        (exactly-one-true
-          (map
-            (lambda (value)
-              (array-ref board col row value))
-            (iota board-size)))))))
+  ;; Each position contains exactly one number
+  (do ((col 0 (1+ col))) ((= col board-size))
+    (do ((row 0 (1+ row))) ((= row board-size))
+      (exactly-one-true
+        (map
+          (lambda (value)
+            (array-ref board col row value))
+          (iota board-size)))))
+
+  (let ((vals (solve-sat)))
+    (do ((row 0 (1+ row))) ((= row board-size))
+      (do ((col 0 (1+ col))) ((= col board-size))
+        (format #t "~a" (get-value board vals col row)))
+      (newline))))