Leetcode_c++： Subsets II (090）

题目

Given a collection of integers that might contain duplicates, nums, return all possible subsets.

Note: The solution set must not contain duplicate subsets.

For example,

If nums = [1,2,2], a solution is:

[

[2],

[1],

[1,2,2],

[2,2],

[1,2],

[]

]

算法

和Subsets I的唯一区别就是添加了两行去重的代码。

http://blog.csdn.net/doc_sgl/article/details/12260731

#include<iostream>
#include<vector>
#include<stack>
#include <algorithm>

using namespace std;

const int N=0;

class Solution {

void findsubset(vector<int> s, int index, vector<int> &subset, vector<vector<int> > &res)
{
res.push_back(subset);
for(int i = index; i< s.size(); i++)
{
if(i!=index && s[i]==s[i-1])continue;
subset.push_back(s[i]);
findsubset(s,i+1,subset,res);
subset.pop_back();
}
}
public:

vector<vector<int> > subsetsWithDup(vector<int> &S) {
// Note: The Solution object is instantiated only once.
vector<vector<int> > res;
sort(S.begin(),S.end());
vector<int> subset;
findsubset(S,0,subset,res);
return res;
}
};