Combination Sum [LeetCode]

Problem Description: http://oj.leetcode.com/problems/combination-sum/　　　　

Basic idea: It seems complicate at first. But once I got the recursive idea, the solution was neat. This code could be not efficient. I will rewrite with dynamic programming next time.

 class Solution {
 public:
     vector<vector<int> > combinationSum(vector<int> &candidates, int target) {
         // Note: The Solution object is instantiated only once and is reused by each test case.
         std::sort(candidates.begin(), candidates.end());
         vector<vector<int> > combinations;
         for(int i = ; i < candidates.size(); i ++) {
             if(candidates[i] > target)
                 break;
             if(candidates[i] == target) {
                 vector<int> combination;
                 combination.push_back(candidates[i]);
                 combinations.push_back(combination);
             }else{
                 if(i ==  && target % candidates[i] != )
                     continue;
                 if(i ==  && target % candidates[i] == ){
                     vector<int> combination(target / candidates[i], candidates[i]);
                     combinations.push_back(combination);
                     continue;
                 }
                 vector<int> sub_candidates(candidates.begin(), candidates.begin() + i + );
                 vector<vector<int> > rests =  combinationSum(sub_candidates, target - candidates[i]);
                 for(auto item: rests){
                     item.push_back(candidates[i]);
                     combinations.push_back(item);
                 }
             }
         }
         return combinations;
     }
 };