POJ 1565 Skew Binary pow函数使用

#include <iostream>
#include <string>
#include <cmath>
using namespace std;
int main(){
string s;
while(1){
cin>>s;
if (s == "0")
break;
long result = 0;
int k = 1;
string::iterator it;
for (it = s.end()-1;it!=s.begin();it--)
{
result += (*it - '0')*(pow(double(2),k++) - 1);
}
result += (*it - '0')*(pow(double(2),k) - 1);
cout<<result<<endl;
}
return 0;
}