C++ Program for Binary to Decimal conversion

#include<iostream>
#include<cmath>
using namespace std;

int main()
{
int num,decimal,calB;
double exp;
cout << "Enter a Binary number: ";
cin >> num;
calB=num;
decimal=exp=0;
while( calB!=0 )
{
decimal+=pow(2.0,exp)*(calB%10);
calB/=10;
exp++;
}
cout << "Decimal of "
<< num
<< " is: "
<< decimal
<< ".\n";

return 0;
}