题目：
Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.
The same repeated number may be chosen from candidates unlimited number of times.
Note:
- All numbers (including
target) will be positive integers. - The solution set must not contain duplicate combinations.
Example 1:
Input: candidates =[2,3,6,7],target =7, A solution set is: [ [7], [2,2,3] ]
Example 2:
Input: candidates = [2,3,5], target = 8,
A solution set is:
[
[2,2,2,2],
[2,3,3],
[3,5]
]
代码：
class Solution {
public:
vector<vector<int>> combinationSum(vector<int>& candidates, int target) {
vector<vector<int>> m;
if (target < 0)return m;
if (target == 0) {
vector<int> v;
m.push_back(v);
return m;
}
sort(candidates.begin(), candidates.end());
for (int i = 0; i < candidates.size(); i++) {
vector<vector<int>> v = combinationSum(candidates, target - candidates[i]);
if (v.size() > 0) {
for (int j = 0; j < v.size(); j++) {
v[j].push_back(candidates[i]);
sort(v[j].begin(), v[j].end());
m.push_back(v[j]);
}
}
}
sort(m.begin(), m.end());
m.erase(unique(m.begin(), m.end()), m.end());
return m;
}
};注：
unique之前需要先sort