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;
}