LeetCode: Combination Sum

题目

https://oj.leetcode.com/problems/combination-sum/

分析

DFS，之前总结过很多道同类型的题。

代码

class Solution
{
public:
vector<vector<int>> combinationSum(vector<int> &candidates, int target)
{
if (candidates.size() == 0)
return res;
this->candidates = candidates;
sort(this->candidates.begin(), this->candidates.end());
vector<int> solution;

DFS(solution, 0, target);

return res;
}
void DFS(vector<int> &solution, int start, int target)
{
if (target == 0)
res.push_back(solution);
else
{
for (int i = start; i < candidates.size() && candidates[i] <= target; i++)
{
solution.push_back(candidates[i]);
DFS(solution, i, target-candidates[i]);
solution.pop_back();
}
}
}
private:
vector<int> candidates;
vector<vector<int>> res;
};