Time Complexity - O(logn)

Space Complexity - O(1)

```
def two_sum(numbers, target)
be = 0
en = numbers.length - 1
while be < en
cur = numbers[be] + numbers[en]
if cur == target
return [be + 1, en + 1]
elsif cur < target
be += 1
else
en -= 1
end
end
end
```