Combination Sum II

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.

Each number in C may only be used once in the combination.

Note:

• All numbers (including target) will be positive integers.
• Elements in a combination (a1, a2, … , ak) must be in non-descending order. (ie, a1 ≤ a2 ≤ … ≤ ak).
• The solution set must not contain duplicate combinations.

For example, given candidate set 10,1,2,7,6,1,5 and target 8, 
A solution set is: 
[1, 7] 
[1, 2, 5] 
[2, 6] 
[1, 1, 6] 

struct Node
{
   int key;
   int cnt;
};
class Solution {
private:
    vector<Node> v;
    vector<Node> data;
    vector<vector< int> > result;
     int len;
    
     void generate( int vdep, int index, int target)
    {
         if(target< 0)  return;
         if(target== 0)
        {
            vector< int> re;
             for( int i= 0;i<vdep;i++)
                 for( int j= 0;j<v[i].cnt;j++)
                    re.push_back(v[i].key);
            result.push_back(re);
             return;
        }
         for( int i=index;i<len;i++)
        {
             for( int j= 1;j<=data[i].cnt;j++)
            {
                v[vdep].key=data[i].key;
                v[vdep].cnt=j;
                generate(vdep+ 1,i+ 1,target-v[vdep].key*j);
            }
        }
    }
public:
    vector<vector< int> > combinationSum2(vector< int> &num,  int target) 
    {
        sort(num.begin(),num.end());
         // group
         int old= 0;
        Node node;
         for( int i= 0;i<num.size();i++)
        {
             if(num[i]==old) data[data.size()- 1].cnt++;
             else
            {
                node.key=num[i];
                old=node.key;
                node.cnt= 1;
                data.push_back(node);
            }
        }
         for( int i= 0;i<num.size();i++)
            v.push_back(node);
                
        result.clear();
        
        len=data.size();
        
        generate( 0, 0,target);
         return result;
    }
};