leetcode[90]Subsets II

Given a collection of integers that might contain duplicates, S, return all possible subsets.

Note:

• Elements in a subset must be in non-descending order.
• The solution set must not contain duplicate subsets.

 

For example,
If S = [1,2,2], a solution is:

[

  [2],

  [1],

  [1,2,2],

  [2,2],

  [1,2],

  []

]

class Solution {

public:

void subset(vector<vector<int>> &res,vector<int> &temp,vector<int> &S,int from)

{

    res.push_back(temp);

    for(int i=from;i<S.size();i++)

    {

        if(i>from&&S[i]==S[i-1])continue;

        temp.push_back(S[i]);

        subset(res,temp,S,i+1);

        temp.pop_back();

    }

}

    vector<vector<int> > subsetsWithDup(vector<int> &S) {

        vector<vector<int>> res;

        res.clear();

        vector<int> temp;

        temp.clear();

        int n=S.size();

        if(n<1)return res;

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

        subset(res,temp,S,0);

        return res;

    }

/*    

void subset(vector<vector<int>> &res,vector<int> &temp,vector<int> &S,int from)

{

    if(from==S.size())

    {

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

        {

            if(res[i]==temp)return;

        }

        res.push_back(temp);

        return;

    }

    temp.push_back(S[from]);

    subset(res,temp,S,from+1);

    temp.pop_back();

    subset(res,temp,S,from+1);

}

    vector<vector<int> > subsetsWithDup(vector<int> &S) {

        vector<vector<int>> res;

        res.clear();

        vector<int> temp;

        temp.clear();

        int n=S.size();

        if(n<1)return res;

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

        subset(res,temp,S,0);

        return res;

    }



void subset(vector<vector<int>> &res,vector<int> &temp,vector<int> &S,int from, int to,int k)

{

    if(k==0)

    {

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

        {

            if(res[i]==temp)return;

        }

        res.push_back(temp);

        return;

    }

    else

    {

        if(from>to)return;

        else

        {

            temp.push_back(S[from]);

            subset(res,temp,S,from+1,to,k-1);

            temp.pop_back();

            subset(res,temp,S,from+1,to,k);

            return;

        }

    }

}

    vector<vector<int> > subsetsWithDup(vector<int> &S) {

        vector<vector<int>> res;

        res.clear();

        vector<int> temp;

        temp.clear();

        int n=S.size();

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

        if(n<1)return res;

        for(int k=0;k<=n;k++)

        {

            subset(res,temp,S,0,n-1,k);

        }

        return res;

    }

*/

};