class Solution {
public:
vector[HTML_REMOVED] st;
vector[HTML_REMOVED] path;
vector[HTML_REMOVED]> ans;

vector<vector<int>> permutation(vector<int>& nums) {
    sort(nums.begin(), nums.end());
    st = vector<bool>(nums.size(), false);
    path = vector<int>(nums.size());
    dfs(nums, 0, 0);
    return ans;
}

void dfs(vector<int>& nums, int u, int start)
{
    if (u == nums.size())
    {
        ans.push_back(path);
        return;
    }

    for (int i = start; i < nums.size(); i ++ )
        if (!st[i])
        {
            st[i] = true;
            path[i] = nums[u];
            if (u + 1 < nums.size() && nums[u + 1] != nums[u])
                dfs(nums, u + 1, 0);
            else
                dfs(nums, u + 1, i + 1);
            st[i] = false;
        }
}

};