Data commit

Task/Recamans-sequence/Nim/recamans-sequence.nim

@@ -0,0 +1,27 @@
+import sequtils, sets, strutils
+
+iterator recaman(num: Positive = Natural.high): tuple[n, a: int; duplicate: bool] =
+  var a = 0
+  yield (0, a, false)
+  var known = [0].toHashSet
+  for n in 1..<num:
+    var next = a - n
+    if next <= 0 or next in known:
+      next = a + n
+    a = next
+    yield (n, a, a in known)
+    known.incl a
+
+echo "First 15 numbers in Recaman’s sequence: ", toSeq(recaman(15)).mapIt(it.a).join(" ")
+
+for (n, a, dup) in recaman():
+  if dup:
+    echo "First duplicate found: a($1) = $2".format(n, a)
+    break
+
+var target = toSeq(0..1000).toHashSet
+for (n, a, dup) in recaman():
+  target.excl a
+  if target.card == 0:
+    echo "All numbers from 0 to 1000 generated after $1 terms.".format(n)
+    break