被11整除的數

#include <string.h>
char line[1001];
int main()
{
int n;
while(scanf("%s",line)==1){
if(strcmp(line,"0")==0)break;

int ans1=0;
int ans2=0;
for(int i=0;line[i]!=0;i++){
if(i%2==0)ans1+=line[i]-'0';
else ans2+=line[i]-'0';
}

if((ans1-ans2)%11==0)printf("%s is a multiple of 11.\n",line);
else printf("%s is not a multiple of 11.\n",line);
}


}