Data commit

Task/Periodic-table/Go/periodic-table.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+    "fmt"
+    "log"
+)
+
+var limits = [][2]int{
+    {3, 10}, {11, 18}, {19, 36}, {37, 54}, {55, 86}, {87, 118},
+}
+
+func periodicTable(n int) (int, int) {
+    if n < 1 || n > 118 {
+        log.Fatal("Atomic number is out of range.")
+    }
+    if n == 1 {
+        return 1, 1
+    }
+    if n == 2 {
+        return 1, 18
+    }
+    if n >= 57 && n <= 71 {
+        return 8, n - 53
+    }
+    if n >= 89 && n <= 103 {
+        return 9, n - 85
+    }
+    var row, start, end int
+    for i := 0; i < len(limits); i++ {
+        limit := limits[i]
+        if n >= limit[0] && n <= limit[1] {
+            row, start, end = i+2, limit[0], limit[1]
+            break
+        }
+    }
+    if n < start+2 || row == 4 || row == 5 {
+        return row, n - start + 1
+    }
+    return row, n - end + 18
+}
+
+func main() {
+    for _, n := range []int{1, 2, 29, 42, 57, 58, 59, 71, 72, 89, 90, 103, 113} {
+        row, col := periodicTable(n)
+        fmt.Printf("Atomic number %3d -> %d, %-2d\n", n, row, col)
+    }
+}