class Solution {
public:
    vector<int> twoSum(vector<int>& numbers, int target) {
        int l = 0;
        int r = numbers.size() - 1;
        int sum;

        while(l < r) {
            sum = numbers[l] + numbers[r];
            if(sum == target)   return {l+1, r+1};
            else if (sum > target) r--;
            else l++;    
        }

        return {};
    }
};