class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        bool found = false;
        vector<int> ans;
        int t = 0, l =0, r=0;
 
        while(r < nums.size() && !found){
            t = target - nums[r];
            l = r + 1;
 
            while(l < nums.size() && !found){
                if(nums[l] == t){
                    ans.push_back(l);
                    ans.push_back(r);
                    found = true;
                    break;
                }
                l++;
            }
            r++;
        }
        return ans;
    }
};

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        
        vector<int> ans;
        unordered_map<int, int> map;
 
        for(int i=0; i<nums.size(); i++){
            if(map.find(target - nums[i]) != map.end()){
                ans.push_back(map[target - nums[i]]);
                ans.push_back(i);
                return ans;
            }
            else 
                map[nums[i]] = i;
        }
        
        return ans;
    }
};