public class Solution {
    public int[] TwoSum(int[] numbers, int target) {
        if(numbers.Length == 0){return null;}
        int[] ret = new int[2];
        int p1 = 0,p2 = numbers.Length - 1;
        while(p1 < p2){
            int temp = numbers[p1] + numbers[p2];
            if(temp == target){
                ret = new int[2]{p1+1,p2+1};
                break;
            }
            else if(temp < target){
                p1++;
            }
            else if(temp > target){
                p2--;
            }
        }
        return ret;
    }
}