Given a set of candidate numbers (C) (without duplicates) 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:
- All numbers (including target) will be positive integers.
- The solution set must not contain duplicate combinations.
For example, given candidate set [2, 3, 6, 7] and target 7,
A solution set is:
[ [7], [2, 2, 3] ]
class Solution { public: vector<vector<int>> combinationSum(vector<int>& candidates, int target) { vector<vector<int>> results; sort(candidates.begin(), candidates.end()); helper(results,vector<int>{},candidates,target,0); return results; } void helper(vector<vector<int>> &results, vector<int> result, vector<int>& c, int target, int index){ if(target == 0){ results.push_back(result); return; } for(int i = index; i < c.size() && target >= c[i]; ++i){ result.push_back(c[i]); helper(results, result, c, target - c[i], i); result.pop_back(); } } };