1+ /*
2+ We have to find all elements of power set of given set as string using bit manipulation
3+
4+
5+ Example 1:
6+ I/p : "sd"
7+ O/p : "", "s", "d", "sd"
8+
9+ Example 2:
10+ I/p : "abc"
11+ O/p : "", "a", "b", "c", "ab", "bc", "ac", "abc"
12+
13+ Formula for Power Set: 2^n , where n is number of elements present in set.
14+
15+ Here, we will be using the formula mentioned above
16+ in the function printPowerSet.
17+ In function printPowerSet Outer function has complexity of 2^n
18+ and inner funtion has complexity of n.
19+ So Time Complexity = Theta(2^n * n)
20+
21+ */
22+ 23+ #include < iostream>
24+ #include < bits/stdc++.h> // we can also use cmath but bits/stdc++.h is prefered more
25+ using namespace std ;
26+ 27+ int printPowerSet (string str) // function to print all elements of power set
28+ {
29+ int n = str.length ();
30+ int pow_Size = pow (2 , n);
31+ 32+ for (int counter = 0 ; counter < pow_Size; counter++) // This for loop will run for 2^n times i.e. to find all elements for powerset
33+ {
34+ for (int j = 0 ; j < n; j++) // This will run for total n times to print elements where the bit is set.
35+ {
36+ if ((counter & (1 << j)) != 0 ) // Check every bit and if bit is set then prints the element of that index.
37+ {
38+ cout << str[j];
39+ }
40+ }
41+ cout << endl;
42+ }
43+ 44+ }
45+ 46+ int main ()
47+ {
48+ string str = " abc" // string to be passed
49+ 50+ printPowerSet (str);
51+ 52+ return 0 ;
53+ }
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