print all subsets of a string
#include <iostream>
using namespace std;
void solve(string s,string op)
{
if(s.size()==0)
{
cout<<op<<endl;
return;
}
string op1=op;
string op2=op;
op2.push_back(s[0]);
s.erase(s.begin()+0);
solve(s,op1);
solve(s,op2);
}
int main()
{
string s;
cin>>s;
string op="";
solve(s,op);
return 0;
}