Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
Each number in C may only be used once in the combination.
Note:
- All numbers (including target) will be positive integers.
- 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:
代码语言：javascript复制[
[1, 7],
[1, 2, 5],
[2, 6],
[1, 1, 6]
]与39类似，只是注意数字不能重复使用
https://cloud.tencent.com/developer/article/1019276
因而开始不用去重，搜索的过程中要注意避免重复搜索相同分支的情况
代码语言：javascript复制class Solution {
public:
void dfs(vector<int> candidates,int target,vector<vector<int>>& result,vector<int> path)
{
if(target==0)
{
result.push_back(path);
return ;
}
int t;
for(int i=candidates.size()-1;i>=0;i--)
{
if(candidates[i]==t)
{
candidates.pop_back();
continue;
}
t=candidates[i];
candidates.pop_back();
if(t>target) continue;
path.push_back(t);
dfs(candidates,target-t,result,path);
path.pop_back();
}
}
vector<vector<int>> combinationSum2(vector<int>& candidates, int target)
{
vector<vector<int>> result;
vector<int> path;
sort(candidates.begin(),candidates.end());
dfs(candidates,target,result,path);
return result;
}
};
