homework/Homework02_PermutationII.cpp at main · Learning356/homework · GitHub

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class Solution {
public:
    vector<bool> num_to_used;
    vector<int> sets;
    vector<vector<int>> ans;
    vector<vector<int>> permuteUnique(vector<int>& nums) {

        sort(nums.begin(),nums.end());
        num_to_used.resize(nums.size());
        FindSubsets(nums,0);

        return ans;
    }

    void FindSubsets(vector<int>& nums, int index){
        if(index == nums.size()){
            ans.push_back(sets);
            return;

        }

        for(int i = 0; i < nums.size(); i++){

            if(i > 0 && nums[i] == nums[i-1] && !num_to_used[i-1] ) continue;
            if(!num_to_used[i]){
                sets.push_back(nums[i]);
                num_to_used[i] = true;
                FindSubsets(nums,index+1);
                sets.pop_back();
                num_to_used[i] = false;
            }


        }

    }
};