Data commit

Task/Periodic-table/Julia/periodic-table.julia

@@ -0,0 +1,23 @@
+const limits = [3:10, 11:18, 19:36, 37:54, 55:86, 87:118]
+
+function periodic_table(n)
+    (n < 1 || n > 118) && error("Atomic number is out of range.")
+    n == 1 && return [1, 1]
+    n == 2 && return [1, 18]
+    57 <= n <= 71 && return [8, n - 53]
+    89 <= n <= 103 && return [9, n - 85]
+    row, limitstart, limitstop = 0, 0, 0
+    for i in eachindex(limits)
+        if limits[i].start <= n <= limits[i].stop
+            row, limitstart, limitstop = i + 1, limits[i].start, limits[i].stop
+            break
+        end
+    end
+    return (n < limitstart + 2 || row == 4 || row == 5) ?
+        [row, n - limitstart + 1] : [row, n - limitstop + 18]
+end
+
+for n in [1, 2, 29, 42, 57, 58, 59, 71, 72, 89, 90, 103, 113]
+    rc = periodic_table(n)
+    println("Atomic number ", lpad(n, 3), " -> ($(rc[1]), $(rc[2]))")
+end