class Solution {

public:

    vector<vector<int>> permute(vector<int>& nums) {

        sort(nums.begin(),nums.end());

        vector<vector<int>> res;

        vector<int> path;

        trackback(res,path,nums);

        return res;

    }

    void trackback(vector<vector<int>> &res,vector<int> &path,vector<int> &nums)

    {

        if(path.size() == nums.size())

        {

            res.push_back(path);

            return ;

        }

        for(auto i:nums)

        {

            auto pos=find(path.begin(),path.end(),i);

            if(pos==path.end())

            {

                path.push_back(i);

                trackback(res,path,nums);

                path.pop_back();

            }

        }

    }

};