ZOJ 1712 Skew Binary

 1 #include<iostream>
 2 #include<string>
 3 #include<cmath>
 4  using namespace std;
 5 
 6 int main()
 7 {
 8     string a;
 9     long num = 0;
10     int count = 1;
11 //    freopen("test.txt", "r", stdin);
12     while (cin >> a && a != "0")
13     {
14         for (int i = a.length() - 1; i >= 0; i--)
15         {
16             num += (a[i] - '0')* (pow ((double)2, count++) - 1 );
17         }
18         cout << num << endl;
19         num = 0;
20         count  = 1;
21     }
22 
23     return 0;
24 }