"""
167. Two Sum II - Input Array Is Sorted
Difficulty: Medium
https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/

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Given a 1-indexed array of integers numbers that is already sorted in
non-decreasing order, find two numbers such that they add up to a
specific target number. Let these two numbers be numbers[index1] and
numbers[index2] where 1 <= index1 < index2 <= numbers.length.

Return the indices of the two numbers index1 and index2, each
incremented by one, as an integer array [index1, index2] of length 2.

The tests are generated such that there is exactly one solution. You
may not use the same element twice.

Your solution must use only constant extra space.

 

Example 1:

Input: numbers = [2,7,11,15], target = 9
Output: [1,2]
Explanation: The sum of 2 and 7 is 9. Therefore, index1 = 1, index2 =
2. We return [1, 2].

Example 2:

Input: numbers = [2,3,4], target = 6
Output: [1,3]
Explanation: The sum of 2 and 4 is 6. Therefore index1 = 1, index2 =
3. We return [1, 3].

Example 3:

Input: numbers = [-1,0], target = -1
Output: [1,2]
Explanation: The sum of -1 and 0 is -1. Therefore index1 = 1, index2
= 2. We return [1, 2].

 

Constraints:

	• 2 <= numbers.length <= 3 * 10^4

	• -1000 <= numbers[i] <= 1000

	• numbers is sorted in non-decreasing order.

	• -1000 <= target <= 1000

	• The tests are generated such that there is exactly one solution.
"""

class Solution:
    def twoSum(self, numbers: List[int], target: int) -> List[int]:
        i = 0
        j = len(numbers) - 1

        while i < j:
            c = numbers[i] + numbers[j]
            if c == target:
                return [i + 1, j + 1]
            elif c < target:
                i+=1
            else:
                j-=1
        return []