Linear Sum Function

main.go

package main

import "fmt"

func calcSum(numbers []int, left int, right int) int {
	sum := 0
	for i := left; i < right; i++ {
		sum += numbers[i]
	}
	return sum
}

func main() {
	numbers := []int{1, 5, 2, 7, 1, 9}
	fmt.Println(calcSum(numbers, 0, len(numbers)))
}