C++ 代码
class Solution {
public:
vector<vector<int>> ans;
vector<int> path;
void dfs(vector<int> & a,int sum,int start)
{
if(sum <0) return ;
if(sum==0) {ans.push_back(path);return ;}
for(int i=start;i<a.size();i++)
{
path.push_back(a[i]);
dfs(a,sum-a[i],i);
path.pop_back();
}
}
vector<vector<int>> combinationSum(vector<int>& candidates, int target) {
dfs(candidates, target,0);
return ans;
}
};