/**
knakul853
**/

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {


        int n = (int)nums.size();
        sort(nums.begin(), nums.end());

        int l = 0;
        int r = n-1;
        while(l < r)
        {
            int sum = nums[l] + nums[r];
            if( sum > target) r--;
            else if( sum < target )l++;
            else return {l, r};
        }

        return {-1, -1};
    }
};

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {


       unordered_map<int,int>mp;

        for(int i=0;i<nums.size();i++){

            if(mp.count(nums[i]) && nums[i]*2 == target){
                return vector<int>{i,mp[nums[i]]};
            }

            mp[nums[i]] = i;
        }

        for(int i=0;i<(int)nums.size();i++){

            int a = nums[i];
            int b = target - a;

            if(mp.count(b) && a!=b){
                return vector<int>{i,mp[b]};
            }
        }
        assert(false);
    }
};