Something

#include<iostream>

#define MAX 10
using namespace std;

int fact(int n);
int pwr(int n,int m);
void bin(int n,int lbit,int arr[]);

int main()
{
    int n = 4,i,j,c=0;
    int arr[4] = {1,2,3,4};
    int ans[4];
    int t = 0;
    
    char str[4];
    
    t = pwr(2,n);
    cout<<"No : "<<t<<endl;
    
    for(i=1;i<=t;i++)
     {
      bin(i,n,ans);
      cout<<"\t\t";
      for(j=0;j<n;j++)
          {
            if(ans[j])
              cout<<arr[j];
          }
      cout<<endl;
     }
     getchar();
    return 0;
}

int fact(int n)
{
    int i=1,pr=1;
    for(;i<=n;i++)
      pr = pr * i;
    return pr;
}

int pwr(int n,int m)
{
    int i=1,pr=1;
    for(;i<=m;i++)
      pr = pr * n;
    return pr;
}

void bin(int n,int lbit,int arr[])
{
     for(int i=lbit-1;i>=0;i--)
              {
              arr[i]= (n >> i) & 1;     
              cout<<arr[i]<<" ";
              }
     cout<<endl;
}