1817650_wa.c

北大大牛代码 1240道题的原代码 超级权威

# include <stdio.h>
void main()
{
 int i, j, n, f, p, sum;
 char s[11];
 gets(s);
 sum = 0;
 for(i = 0; s[i] != '\0' ; i++)
 if(s[i] == '?') 
 break;
 f = 10 - i;
 n = 11;
 for(j = 0; j < 9; j++)
 {
 --n;
 if(j!=i)
	 sum += (s[j] - 48) * n;
 }
 if(s[9]=='X') sum += 10;
 else sum += s[9] - 48;
 p = -1;
 for(j = 0; j < 10; j++)
 if((sum+j*f)%11==0)
 {p = j;break;}
 printf("%d\n",p);
}