c 2b 2b generate all subsets

1#include <vector>
2#include <iostream>
3#include <cmath>
4using namespace std;
5
6int main() {
7	// this is the length of the array of values
8	// change variable "len" accordingly
9	int len = 5;
10	// this is the array of values
11	int values[] = {3, 4, 2, 8, 5};
12	
13	// all subsets will be in vector "subsets"
14	vector<vector<int>> subsets;
15	for (int i = 0; i < pow(2, len); i++) {
16		int t = i;
17		vector<int> v;
18		for (int j = 0; j < len; j++) {
19			if (t & 1)
20				v.push_back(values[j]);
21			t >>= 1;
22		}
23		subsets.push_back(v);
24	}
25
26	// print all of the subsets (optional)
27	cout << "subsets:\n";
28	for (const vector<int>& subset: subsets) {
29		for (const int& value: subset)
30			cout << value << " ";
31		cout << "\n";
32	}
33	// note: an empty line will be printed at the top,
34	// indicating an empty subset
35}
36

1#include <iostream>
2#include <vector>
3#include <algorithm>
4using namespace std;
5 
6// Function to print the elements of a vector
7void printVector(vector<int> const &out)
8{
9    for (int i: out)
10        cout << i << " ";
11    cout << '\n';
12}
13 
14// Recursive function to print all distinct subsets of S
15// S    --> input set
16// out  --> vector to store subset
17// i    --> index of next element in set S to be processed
18void findPowerSet(int S[], vector<int> &out, int i)
19{
20    // if all elements are processed, print the current subset
21    if (i < 0)
22    {
23        printVector(out);
24        return;
25    }
26 
27    // include current element in the current subset and recur
28    out.push_back(S[i]);
29    findPowerSet(S, out, i - 1);
30 
31    // exclude current element in the current subset
32    out.pop_back(); // backtrack
33 
34    // remove adjacent duplicate elements
35    while (S[i] == S[i-1])
36        i--;
37 
38    // exclude current element in the current subset and recur
39    findPowerSet(S, out, i - 1);
40}
41 
42// Program to generate all distinct subsets of given set
43int main()
44{
45    int S[] = { 1, 3, 1 };
46    int n = sizeof(S) / sizeof(S[0]);
47 
48    // sort the set
49    sort(S, S + n);
50 
51    // create an empty vector to store elements of a subset
52    vector<int> out;
53    findPowerSet(S, out, n-1);
54 
55    return 0;
56}
57