HDU 1013

include<stdio.h>#include<string.h>char str[1000];int main(){    int sum,k,i,j;    while(~scanf("%s",str)&&strcmp(str,"0"))    {        sum = 0;        k = strlen(str);        for(i = 0;i < k;i++)        {            sum += str[i]-48;            if(i==(k-1)&&sum>9)            {                memset(str,0,k);                for(j = 0;sum;j++)                {                    str[j] = sum%10+48;                    sum /= 10;                }                i = -1;                k = j;            }        }        printf("%d\n",sum);    }    return 0;}

#include<stdio.h>int main(){ int i,m; char s[1000]; while(scanf("%s",s)==1&&s[0]!='0'){   for(m=i=0;s[i];i++)     m+=s[i]-'0'; printf("%d\n",m%9==0?9:m%9);  } return 0;}