Data commit

Task/Periodic-table/Nim/periodic-table.nim

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+import std/strformat
+
+const Limits = [3..10, 11..18, 19..36, 37..54, 55..86, 87..118]
+
+func periodicTable(n: Positive): (int, int) =
+  doAssert n in 1..118, "Atomic number is out of range."
+  if n == 1: return (1, 1)
+  if n == 2: return (1, 18)
+  if n in 57..71: return (8, n - 53)
+  if n in 89..103: return (9, n - 85)
+  var row, start, stop = 0
+  for i, limit in Limits:
+    if n in limit:
+      row = i + 2
+      start = limit.a
+      stop = limit.b
+      break
+  if n < start + 2 or row == 4 or row == 5:
+    return (row, n - start + 1)
+  result = (row, n - stop + 18)
+
+for n in [1, 2, 29, 42, 57, 58, 59, 71, 72, 89, 90, 103, 113]:
+  let (row, col) = periodicTable(n)
+  echo &"Atomic number {n:3} → {row}, {col}"