Two Sum II — Sorted Array

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.

Return the indices of the two numbers, [index1, index2], as an integer array of length 2 where 1 <= index1 < index2 <= numbers.length.

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]

Constraints

• 2 <= numbers.length <= 3 * 10^4
• -1000 <= numbers[i] <= 1000
• numbers is sorted in non-decreasing order.
• Exactly one valid solution exists.