Data commit

Task/Van-Eck-sequence/CLU/van-eck-sequence.clu

@@ -0,0 +1,31 @@
+% Generate the first N elements of the Van Eck sequence
+eck = proc (n: int) returns (array[int])
+    ai = array[int]
+    e: ai := ai$fill(0, n, 0)
+
+    for i: int in int$from_to(ai$low(e), ai$high(e)-1) do
+        for j: int in int$from_to_by(i-1, ai$low(e), -1) do
+            if e[i] = e[j] then
+                e[i+1] := i-j
+                break
+            end
+        end
+    end
+    return(e)
+end eck
+
+% Show 0..9 and 990..999
+start_up = proc ()
+    po: stream := stream$primary_output()
+    e: array[int] := eck(1000)
+
+    stream$puts(po, "  0 -   9: ")
+    for i: int in int$from_to(0,9) do
+        stream$putright(po, int$unparse(e[i]), 4)
+    end
+    stream$puts(po, "\n990 - 999: ")
+    for i: int in int$from_to(990,999) do
+        stream$putright(po, int$unparse(e[i]), 4)
+    end
+    stream$putl(po, "")
+end start_up