Given an array of integers numbers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.
Return the indices of the two numbers (1-indexed) as an integer array answer of size 2, where 1 <= answer[0] < answer[1] <= numbers.length.
You may assume that each input would have exactly one solution and you may not use the same element twice.
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]
Example 3:
Input: numbers = [-1,0], target = -1
Output: [1,2]
Solution in Java :
class Solution {
public int[] twoSum(int[] numbers, int target) {
int i = 0, j = numbers.length - 1;
while (i < j) {
int x = (numbers[i] + numbers[j]);
if (x == target) {
int[] result = new int[2];
result[0] = i + 1;
result[1] = j + 1;
return result;
} else if (x < target) i++;
else j--;
}
return new int[2];
}
}