Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.
The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2.
Note:
<li>Your returned answers (both index1 and index2) are not zero-based.</li>
<li>You may assume that each input would have <em>exactly</em> one solution and you may not use the <em>same</em> element twice.</li>
Example:
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.