// MARK: - 167. Two Sum II - Input Array Is Sorted

func twoSum(_ numbers: [Int], _ target: Int) -> [Int] {
    var l = 0
    var r = numbers.count - 1

    while l < r {
        let sum = numbers[l] + numbers[r]
        if sum < target {
            l += 1
        } else if sum > target {
            r -= 1
        } else {
            return [l+1, r+1]
        }
    }
    return []
}