题目：
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.
Example
Given candidate set [10,1,6,7,2,1,5] and target 8,
A solution set is:
[
[1,7],
[1,2,5],
[2,6],
[1,1,6]
]题解：
主要是去重复，多个方法，之前已经介绍过。利用set
Solution 1 ()
class Solution {
public:
vector<vector<int> > combinationSum2(vector<int> &num, int target) {
vector<vector<int> > res;
vector<int> cur;
sort(num.begin(), num.end());
dfs(res, cur, num, target, );
return res;
}
void dfs(vector<vector<int> > &res, vector<int> &cur, vector<int> &num, int target, int pos){
if (!num.empty() && target == ) {
res.push_back(cur);
return;
}
for (int i = pos; i < num.size(); ++i) {
if(i > pos && num[i] == num[i-]) {
continue;
}
if (target - num[i] >= ) {
cur.push_back(num[i]);
dfs(res, cur, num, target - num[i], i + );
cur.pop_back();
} else {
break;
}
}
}
};