langs a-z

Task/Matrix-multiplication/OCaml/matrix-multiplication-1.ocaml

@@ -0,0 +1,13 @@
+let matrix_multiply x y =
+  let x0 = Array.length x
+  and y0 = Array.length y in
+  let y1 = if y0 = 0 then 0 else Array.length y.(0) in
+  let z = Array.make_matrix x0 y1 0 in
+  for i = 0 to x0-1 do
+    for j = 0 to y1-1 do
+      for k = 0 to y0-1 do
+        z.(i).(j) <- z.(i).(j) + x.(i).(k) * y.(k).(j)
+      done
+    done
+  done;
+  z

Task/Matrix-multiplication/OCaml/matrix-multiplication-2.ocaml

@@ -0,0 +1,17 @@
+(* equivalent to (apply map ...) *)
+let rec mapn f lists =
+  assert (lists <> []);
+  if List.mem [] lists then
+    []
+  else
+    f (List.map List.hd lists) :: mapn f (List.map List.tl lists)
+
+let matrix_multiply m1 m2 =
+  List.map
+    (fun row ->
+      mapn
+       (fun column ->
+         List.fold_left (+) 0
+          (List.map2 ( * ) row column))
+       m2)
+    m1