UVa 10878 Decode the tape

UVa 10878 Decode the tape

将tape中的'o'变换成1，' '变换成0，'.'不用管，得到的二进制整数就是对应的字符ASCII码。
以下是我的代码：

#include < iostream >
#include < string >
#include < cstdio >
using   namespace  std;

int  main()
{
     /*
    freopen("data.in","r",stdin);
    freopen("data.out","w",stdout);
    // */

     string  tape;
    getline(cin,tape);
     while (getline(cin,tape)  &&  tape != " ___________ " )
    {
         char  ch( 0 );
         for ( int  i = tape.size() - 2 ,j = 1 ;i >= 2 ;i -- )
        {
             if (tape[i] == ' . ' )
                 continue ;
             if (tape[i] == ' o ' )
            {
                ch += j;
                j *= 2 ;
            }
             else   if (tape[i] == '   ' )
                j *= 2 ;
        }
        cout << ch;
    }

     return   0 ;
}