78. 子集 - Subsets

 1 class Solution {
 2 public:
 3     vector<vector<int>> subsets(vector<int>& nums) {
 4         vector<vector<int>> output;
 5         output.push_back({});
 6         
 7         for (int i = 0; i < nums.size(); i++){
 8             int size = output.size(); 
 9
 
             for (int j = 0; j < size; j++){ 
10                 auto sub = output[j]; 
11                 sub.push_back(nums[i]); 
12                 output.push_back(sub);
13             }
14         }
15         return output;
16     }
17 };

90. 子集 - Subsets II

 1 class Solution {
 2 public:
 3
 
     vector<vector<int>> subsetsWithDup(vector<int>& nums) {
 4         sort(nums.begin(), nums.end());
 5         vector<vector<int>> output;
 6         output.push_back({});
 7         
 8         for (int i = 0; i < nums.size(); i++){
 9             int size = output.size();
 
10             for (int j = 0; j < size; j++){
11                 auto temp = output[j];
12                 temp.push_back(nums[i]);
13                 // handle duplicate cases
14                 bool found = false;
15                 // find whether there is a duplicate case
16                 for (int k = 0; k < output.size(); k ++){
17                     if (temp == output[k]){
18                         found = true;
19                         break;
20                     }
21                 }
22                 
23                 if(!found)
24                     output.push_back(temp);
25             }
26         }
27         
28         return output;
29     }
30 };