Data commit

Task/Zig-zag-matrix/Standard-ML/zig-zag-matrix.ml

@@ -0,0 +1,17 @@
+fun rowprint r = (List.app (fn i => print (StringCvt.padLeft #" " 3 (Int.toString i))) r;
+                  print "\n");
+fun zig lst M  =  List.app rowprint (lst M);
+
+fun sign t = if t mod 2 = 0 then ~1 else 1;
+
+fun zag n = List.tabulate (n,
+            fn i=> rev ( List.tabulate (n,
+                        fn j =>
+			     let val t = n-j+i  and  u =  n+j-i  in
+			         if i <= j
+                                    then   t*t div 2 + sign t * ( t div 2 - i )
+                                    else   n*n - 1 - ( u*u div 2 + sign u * ( u div 2 - n + 1 + i) )
+	                      end
+			 )));
+
+zig zag 5 ;