openjudge 2973

 1 #include<stdio.h>
 2 #include<string.h>
 3 #include<math.h>
 4 int tran2ten(char * data)
 5 {
 6     int i = 0;
 7     int len = strlen(data);
 8     if(len == 1 && data[0] == ‘0‘)
 9         return -1;
10     int x = 0,r = 0;
11     while(len>0)
12     {
13         x = *(data++) - ‘0‘;
14         r +=x*(pow(2,len)-1);
15         len--;
16         if(x == 2)
17             break;
18     }
19     printf("%d\n",r);
20     return r;
21 }
22 int main(void)
23 {
24     char data[32];
25     while(1)
26     {
27         scanf("%s", data);
28         if(tran2ten(data) == -1)
29             break;
30 
31     }
32 }