Initial data commit

Task/Subtractive-generator/Icon/subtractive-generator.icon

@@ -0,0 +1,26 @@
+procedure main()
+   every 1 to 10 do
+      write(rand_sub(292929))
+end
+
+procedure rand_sub(x)
+static ring,m
+   if /ring then {
+      m := 10^9
+      every (seed | ring) := list(55)
+      seed[1] := \x | ?(m-1)
+      seed[2] := 1
+      every seed[n := 3 to 55] := (seed[n-2]-seed[n-1])%m
+      every ring[(n := 0 to 54) + 1] := seed[1 + (34 * (n + 1)%55)]
+      every  n := *ring to 219 do {
+         ring[1] -:= ring[-24]
+         ring[1] %=  m
+         put(ring,get(ring))
+         }
+   }
+   ring[1] -:= ring[-24]
+   ring[1] %:= m
+   if ring[1] < 0 then ring[1] +:= m
+   put(ring,get(ring))
+   return ring[-1]
+end