Combination Sum
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:
- All numbers (including target) will be positive integers.
- Elements in a combination (a1, a2, … , ak) must be in non-descending order. (ie, a1 ≤ a2 ≤ … ≤ ak).
- 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 {
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;
}
};