void DFS(int depth, int size, vector<bool> &hash, vector<int> num, vector<int> &result, vector<vector<int> > &ans)

{

if(depth==size)

{

ans.push_back(result);

return ;

}

int left=0, right;

while(left<size)

{

if(hash[left]==false)

{

result[depth]=num[left];

hash[left]=true;

DFS(depth+1, size, hash, num, result, ans);

hash[left]=false;

right=left+1;

while(right<size&&num[left]==num[right])

right++;

left=right;

}

else

left++;

}

}

vector<vector<int> > permuteUnique(vector<int> &num) {

// Start typing your C/C++ solution below

// DO NOT write int main() function

vector<vector<int> > ans;

vector<int> result;

vector<bool> hash;

if(num.size()==0)

return ans;

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

int size=num.size();

result.resize(size);

for(int i=0;i<size;i++)

hash.push_back(false);

DFS(0, size, hash, num, result, ans);

return ans;

}