Combination Sum II

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in Cwhere 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]

 

class Solution {
public:
vector<vector<int> >res;
vector<vector<int> > combinationSum2(vector<int> &num, int target)
{
res.clear();
sort(num.begin(), num.end());
vector<int> path;
execute(num, target, 0, path);
return res;
}
void execute(vector<int> &num, int target, int pos, vector<int> &path)
{
for (int i = pos; i < num.size(); i++)
{
if( i > pos && num[i] == num[i - 1])
continue;
if (target < num[i])
return;
path.push_back(num[i]);
if (target == num[i])
{
res.push_back(path);
path.pop_back();
return;
}
execute(num, target - num[i], i + 1, path);
path.pop_back();
}
}
};