2441. Largest Positive Integer That Exists With Its Negative

class Solution {
public:
    int findMaxK(vector<int>& nums) 
    {
        sort(nums.begin(), nums.end());

        int i=0, j=nums.size()-1;


        while(i<j)
        {
            if(nums[i]==-nums[j])
                return nums[j];
            else if(nums[i]>-nums[j])
                j--;
            else 
                i++;
        }

        return -1;
    }
};