class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        int n = nums.size();
        vector<int> idxs;
        for(int i = 0; i < n; i++) idxs.push_back(i);

        // Can't be sorted directly
        sort(idxs.begin(), idxs.end(), [&nums](int i, int j){
            return nums[i] < nums[j];
        });
        int l = 0, r = n - 1;
        vector<int> res;
        while(l < r){
            int sum = nums[idxs[l]] + nums[idxs[r]];
            if(sum == target){
                res.push_back(idxs[l]);
                res.push_back(idxs[r]);
                break;
            }else if(sum > target){
                r--;
            }else{
                l++;
            }
        }
        return res;
    }
};