UVa 575Skew Binary

#include <cstdio>#include <cmath>#include <iostream>#include <cstring>const int MAX = 50;char num[50];using namespace std;int main (){   #ifndef ONLINE_JUDGE    freopen("in.txt", "r", stdin);    #endif    while(scanf("%s", num) == 1) {        int len = strlen(num);        int sum = 0;        for(int i=0; i<len; i++) {            sum += (num[i]-'0')*((1<<(len-i)) - 1);        }        if(sum == 0) break;        printf("%d\n",sum);    }    return 0;}