Two Sum

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        vector < pair < int, int > > idx;
        for(int i = 0; i < nums.size(); i++)
            idx.push_back({nums[i], i});
        sort(idx.begin(), idx.end());
        int l = 0, r = nums.size() - 1;
        while(l < r){
            if(idx[l].first + idx[r].first == target) return {idx[l].second, idx[r].second};
            (idx[l].first + idx[r].first > target ? r-- : l++);
        }
        return {-1, -1};
    }
};