leetcode 48: Subsets II

Jun 25 '12

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:
    vector<vector<int> > subsets(vector<int> &S) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<vector<int> > rel;
        if( S.size() < 1) return rel;
        vector<int> temp;
        rel.push_back(temp);
        sort( S.begin(), S.end() );
        subsetsRec( rel, S, temp, 0);
        
        return rel;
        
    }

private:
    void subsetsRec( vector<vector<int> > & rel, vector<int>& s, vector<int>& temp, int level) {
        for( int i=level; i<s.size(); i++) {
            temp.push_back( s[i] );
            rel.push_back( temp);
            subsetsRec( rel, s, temp, i+1);
            temp.pop_back();
            
            while( s[i] == s[i+1] ) i++;
	    if( i==s.size()-1) return;}}};

 

public class Solution {
    public ArrayList<ArrayList<Integer>> subsetsWithDup(int[] num) {
        // Start typing your Java solution below
        // DO NOT write main() function        
        //Arrays.sort( num );
        ArrayList<ArrayList<Integer>> rel = new ArrayList<ArrayList<Integer>>();
        ArrayList<Integer> temp = new ArrayList<Integer>();
        rel.add(temp);
        
        Arrays.sort( num );
        subsetsRec(rel, temp, num, 0); 
        
        return rel;
    }
    
    private void subsetsRec(ArrayList<ArrayList<Integer>> rel, ArrayList<Integer> temp, int[] num, int level){
        
        
        for(int i=level; i<num.length; i++) {
            temp.add( num[i] );
            rel.add( new ArrayList<Integer>(temp)  );
            
            subsetsRec(rel, temp, num, i+1);
            
            temp.remove(temp.size() -1);
            
            while(i<num.length-1 && num[i] == num[i+1] ) i++;
            
        }
        
        if(level == num.length - 1) return;
    }
}