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#include <map>

using namespace std;

class Solution {
public:
    vector<vector<int>> ans;
    map<vector<int>, int> markmap;
    bool flag[100000];
    int sum;
    
    vector<vector<int>> permuteUnique(vector<int> &num) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        ans.clear();
        markmap.clear();
        sum = num.size();
        for(int i = 0; i < sum; i++) {
            flag[i] = false;
        }
        for(int i = 0; i < sum; i++) {
            flag[i] = true;
            vector<int> tmp(sum);
            tmp[0] = i;
            fun(tmp, 1, num);
            flag[i] = false;
        }
        return ans;
    }
    
    void fun(vector<int> &tmp, int k, vector<int> &num) {
        if(k >= sum) {
            vector<int> numtmp(sum);
            for(int i = 0; i < sum; i++) {
                numtmp[i] = num[tmp[i]];
            }
            map<vector<int>, int>::iterator l_it = markmap.find(numtmp);
            if(markmap.empty() || l_it == markmap.end()) {
                ans.push_back(numtmp);
                markmap[numtmp] = 590;
            }
            return;
        }
        for(int i = 0; i < sum; i++) {
            if(!flag[i]) {
                flag[i] = true;
                tmp[k] = i;
                fun(tmp, k + 1, num);
                flag[i] = false;
            }
        }
    }
};