uva 575(数学)

题解：题目中已给公式，用循环求解。

#include <iostream>#include <cstdio>#include <cmath>#include <cstring>using namespace std;const int N =50;int main() {char s[N];int ans;while (scanf("%s", s)) {if (s[0] == '0')break;ans = 0;int len = strlen(s);for (int i = 0, j = len; i < len; i++, j--)ans += (s[i] - '0') * (pow(2, j) - 1);printf("%d\n", ans);}return 0;}