Data commit

Task/Determinant-and-permanent/Ol/determinant-and-permanent.ol

@@ -0,0 +1,66 @@
+; helper function that returns rest of matrix by col/row
+(define (rest matrix i j)
+   (define (exclude1 l x) (append (take l (- x 1)) (drop l x)))
+   (exclude1
+      (map exclude1
+         matrix (repeat i (length matrix)))
+      j))
+
+; superfunction for determinant and permanent
+(define (super matrix math)
+   (let loop ((n (length matrix)) (matrix matrix))
+      (if (eq? n 1)
+         (caar matrix)
+         (fold (lambda (x a j)
+                  (+ x (* a (lref math (mod j 2)) (super (rest matrix j 1) math))))
+            0
+            (car matrix)
+            (iota n 1)))))
+
+
+; det/per calculators
+(define (det matrix) (super matrix '(-1 1)))
+(define (per matrix) (super matrix '( 1 1)))
+
+; ---=( testing )=---------------------
+(print (det '(
+   (1 2)
+   (3 4))))
+; ==> -2
+
+(print (per '(
+   (1 2)
+   (3 4))))
+; ==> 10
+
+
+(print (det '(
+   ( 1  2  3  1)
+   (-1 -1 -1  2)
+   ( 1  3  1  1)
+   (-2 -2  0 -1))))
+; ==> 26
+
+(print (per '(
+   ( 1  2  3  1)
+   (-1 -1 -1  2)
+   ( 1  3  1  1)
+   (-2 -2  0 -1))))
+; ==> -10
+
+
+(print (det '(
+   ( 0  1  2  3  4)
+   ( 5  6  7  8  9)
+   (10 11 12 13 14)
+   (15 16 17 18 19)
+   (20 21 22 23 24))))
+; ==> 0
+
+(print (per '(
+   ( 0  1  2  3  4)
+   ( 5  6  7  8  9)
+   (10 11 12 13 14)
+   (15 16 17 18 19)
+   (20 21 22 23 24))))
+; ==> 6778800