Add arrays package

arrays/sum.go

@@ -7,3 +7,17 @@ func Sum(numbers []int) int {
 	}
 	return sum
 }
+
+func SumAllTails(numbersToSum ...[]int) []int {
+	sums := make([]int, 0, len(numbersToSum))
+
+	for _, numbers := range numbersToSum {
+		if len(numbers) == 0 {
+			sums = append(sums, 0)
+		} else {
+			tail := numbers[1:]
+			sums = append(sums, Sum(tail))
+		}
+	}
+	return sums
+}