047. Permutations II.cpp

class Solution {
public:
    vector<vector<int>> permuteUnique(vector<int>& nums) {
        sort(nums.begin(), nums.end());
        vector<vector<int>>res;
        DFS(res, nums, 0);
        return res;        
    }
    
    void DFS(vector<vector<int>>& res, vector<int> nums, int pos){
        if(pos == nums.size() - 1){
            res.push_back(nums);
            return;
        }
        for(int i = pos; i < nums.size(); i++){
            if(i != pos && nums[i] == nums[pos]) continue;
            swap(nums[pos], nums[i]);
            DFS(res, nums, pos + 1);
        }
    }
};