Binary to Decimal Number Conversion

/* C++ Program for binary to decimal number conversion */
#include<bits/stdc++.h>  
using namespace std;  
long int convert(long int);  
int main()  
{  
    // Scan the binary number  
    long int binary;  
    cout<<"Enter the binary number : ";  
    cin>>binary;  
      
    //Call the convert function  
    long int decimal = convert(binary);  
      
    //Printing the decimal equivalent  
    cout<<"The decimal equivalent of "<<binary<<" is "<<decimal;  
}  
long int convert(long int binary)  
{  
    long int res = 0;  
    int i = 0;   
    while(binary > 0)  
    {  
        int digit = binary % 10; /* Extracting the last digit */  
        res = res + (digit * pow(2,i)); /* Putting it into formula */  
        binary =  binary/10;  
        i++;  
    }  
    return res;  
}