LeetCode Problem: Two Sum

Problem statement:

Given an array of integers (numbers) and a sum (targetSum), you have to return two indices for which the sum of the values is equal to targetSum

Golang Solution:
func twoSum(numbers []int, targetSum int) []int {
    tempMap := map[int]int{}
    for index, val := range numbers {
        if res, ok := tempMap[targetSum-val]; ok {
            return []int{index, res}
        } else {
            tempMap[val] = index
    return []int{-1, -1}