Leetcode Combination Sum II

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations inC where the candidate numbers sums to
T.
Each number in C may only be usedonce 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]
递归遍历，看看和是否等于8，注意在同一层中，两个相等值只能选择一次。

class Solution {
public:
void combin(vector<vector<int> > &res,vector<int> &temp,vector<int> &num,int target,int cur){
if(target==0){
res.push_back(temp);
return;
}else if(target<0)return;
else{
for(int i=cur;i<num.size();i++){
if(i!=cur&&num[i]==num[i-1])continue; //同一层中，两个相等值只能选择一次
temp.push_back(num[i]);
combin(res,temp,num,target-num[i],i+1);
temp.pop_back();
}
}
}
vector<vector<int> > combinationSum2(vector<int> &num, int target) {
vector<vector<int> > res;
if(num.size()==0)return res;
sort(num.begin(),num.end());
vector<int> temp;
combin(res,temp,num,target,0);
return res;
}
};