HDOJ1013大数处理

import java.util.Scanner;

public class problem1013 {

public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner scan=new Scanner(System.in);
String numstr;
while(true){
numstr=scan.next();
int num=0;
for(int i=0;i<numstr.length();i++){
num+=numstr.charAt(i)-'0';
}
if(num==0) break;
int result=num;
while(num>9){
result=caculatedigitssum(num);
num=result;
}
System.out.println(result);
}
}

static int caculatedigitssum(int num){
int digitssum=0;
while(num>0){
digitssum+=num%10;
num/=10;
}
return digitssum;
}

}