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>> res; sort(candidates.begin(),candidates.end()); vector<int> combination; combinationSum(candidates, target, res,combination, 0); return res; } private: void combinationSum(vector<int>& candidates, int target, vector<vector<int>>& res,vector<int>& combination, int begin){ if(!target) { res.push_back(combination); return; } for(int i = begin; i < candidates.size() && target >= candidates[i];++i){ combination.push_back(candidates[i]); combinationSum(candidates,target - candidates[i], res, combination, i); combination.pop_back(); } } };