Finding subsets

# include <algorithm>
# include <iostream>
# include <cstdio>
# include <cmath>
# include <cstdlib>
# include <map>
# include <cmath>
# include <vector>
# include <cstring>

using namespace std;

# define FOR(i, a, b) for (int i=a; i<b; i++)
# define REP(i, a) FOR(i,0,a)
# define all(c) (c).begin(), (c).end()
# define sz(x) x.size()
# define pb push_back
# define UNQ(s) {sort(all(s));(s).erase(unique(all(s)),s.end());}
# define VS vector<string>
# define rive(s) reverse(s.begin(),s.end())

VS Customers,List,lists;
map<string,int>Candidate;

//checking the frequent number of subsets

//finding Subsets
long pow(long a,long b)     /*finds a power of b*/
{
long i,j=1;
for(i=1;i<=b;i++)
j*=a;
return j;
}

long bin(int n)            /*converts into binary equivalent */
{
long i=0,j=1,r;
while(n)
{
r=n%2;
i=i+r*j;
n/=2;
j*=10;
}
return i;
}

void sublist(string a)
{
    long i,j,k,m,l=0,n=0;

    while(a[l])
    l++;
    string ss="";VS final;
    for(i=1;i<pow(2,l);i++)
    {
        k=bin(i);
        m=l-1;

        while(m>=0)
        {
            j=k/pow(10,m);
            if(j==1)
                ss.pb(a[l-1-m]);
            k=k%pow(10,m);
            m--;
        }
        final.pb(ss);
        ss.clear();
    }
    REP(i,sz(final))cout<<final[i]<<endl;
}

int main()
{
    string a;cin>>a;sublist(a);
cout<<"\n\n\n\n\n\n\nDesigned by Iftekhar ahmed eather,\nStudent of CSE (07 batch),\nBUBT, Mirpur";
    return 0;
}