Two Sum II - Input Array Is Sorted

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`, **added 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. ``` **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. ``` **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. ```