two-sum.go

func twoSum(nums []int, target int) []int {
    m := make(map[int]int, len(nums))

    for i, x := range nums {
        y := target - x

        if v, ok := m[y]; ok {
            return []int{v, i}
        }

        m[x] = i
    }

    return []int{}
}