LeetCode 090 Subsets II

class Solution {
public:
void dfs(int step,int nn,int limit,vector<int>temp,vector<vector<int>>&ans,vector<int>nums){
ans.push_back(temp);
if(step==nn)return ;
for(int ii=1;ii<=nn;ii++){
if(ii<=limit)continue;
if(step+1>temp.size())temp.push_back(nums[ii-1]);
else {
if(temp[step]==nums[ii-1])continue;//判断是不是和前面的一个数字相同。
temp[step]=nums[ii-1];
}
dfs(step+1,nn,ii,temp,ans,nums);
}
}
vector<vector<int>> subsetsWithDup(vector<int>& nums) {
vector<vector<int>>ans;
vector<int>temp;
int len=nums.size();
sort(nums.begin(),nums.end());
dfs(0,len,0,temp,ans,nums);
return ans;
}
};