Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
The same repeated number may be chosen from C unlimited number of times.
Note:
For example, given candidate set 2,3,6,7 and
target 7,
A solution set is:
[7]
[2, 2, 3]
class Solution {
vector<vector<int> > result;
vector<int> res;
public:
void dfs(vector<int>& candidates, int target, int start) {
if (target <= 0) {
if(target == 0){
result.push_back(res);
}
return;
}
for (int i = start; i < candidates.size(); i++) {
res.push_back(candidates[i]);
dfs(candidates, target - candidates[i], i);
res.pop_back();
}
}
vector<vector<int> > combinationSum(vector<int> &candidates, int target) {
sort(candidates.begin(), candidates.end());
dfs(candidates, target, 0);
return result;
}
};
原文：http://blog.csdn.net/starcuan/article/details/18865937