Q11332: Summing Digits

原文

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=2307

中譯

http://luckycat.kshs.kh.edu.tw/homework/q11332.htm

#include "stdio.h"

int f(int n)
{
  int tmp = 0;
  while( n )
  {
 if( n >= 10 )
   tmp += n % 10;
 else
   tmp += n;
 n = n / 10;
  }
  if( tmp >= 10 )
 return f(tmp);
  else
 return tmp;
}
int main()
{
  int n;
  while (scanf(" %d",&n) != EOF && n )
  {
 printf("%d\n",f(n));
  }  
  return 0;
}