generate subsequences of string
// CPP program to generate power set in
// lexicographic order.
#include <bits/stdc++.h>
using namespace std;
// str : Stores input string
// n : Length of str.
// curr : Stores current permutation
// index : Index in current permutation, curr
void printSubSeqRec(string str, int n, int index = -1,
string curr = "")
{
// base case
if (index == n)
return;
if (!curr.empty()) {
cout << curr << "\n";
}
for (int i = index + 1; i < n; i++) {
curr += str[i];
printSubSeqRec(str, n, i, curr);
// backtracking
curr = curr.erase(curr.size() - 1);
}
return;
}
// Generates power set in lexicographic
// order.
void printSubSeq(string str)
{
printSubSeqRec(str, str.size());
}
// Driver code
int main()
{
string str = "cab";
printSubSeq(str);
return 0;
}