# [Two Sum II](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/solution/)
###### tags: `Leetcode`, `Medium`, `Two Pointers`
## Approach
* Initialize two pointers `left` and `right` to `0` and `len(nums) - 1`
* If sum of numbers at left and right index add up to sum; return `[nums[left], nums[right]]`
* If sum of numbers is < target; increment left by one
* If sum of numbers is > target; decrement right by one
* Return `[]`
## Asymptotic Analysis
### Time Complexity: **O(N)**
### Space Complexity: **O(1)**
## Code
``` python
from typing import List
class TwoSumII:
@staticmethod
def twoSum(numbers: List[int], target: int) -> List[int]:
left, right = 0, len(numbers) - 1
while left < right:
current_sum = numbers[left] + numbers[right]
if current_sum == target:
return [left + 1, right + 1]
elif current_sum > target:
right -= 1
else:
left += 1
return []
nums, t = [2, 3, 4], 6
print(TwoSumII.twoSum(nums, t))
```