Leetcode Combination Sum II

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums toT.

Each number in C may only be used once in the combination.

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

10,1,2,7,6,1,5

and target

8

,
A solution set is:

[1, 7]

[1, 2, 5]

[2, 6]

[1, 1, 6]

暴力搜索

class Solution {
public:
vector<vector<int> > res;
vector<int> path;
vector<int> candidates;
int target;

void solve(int start, int sum){
if(sum > target) return;
if(sum == target){
if(find(res.begin(),res.end(),path)==res.end())
res.push_back(path);
return;
}
for(int i = start; i < candidates.size(); ++ i){
path.push_back(candidates[i]);
solve(i+1,sum+candidates[i]);
path.pop_back();
}
}

vector<vector<int> > combinationSum2(vector<int> &candidates, int target) {
this->candidates = candidates;
this->target = target;
sort(this->candidates.begin(),this->candidates.end());
solve(0,0);
return res;
}
};