zoj1115-----------Digital Roots

Background

The digital root of a positive integer is found by summing the digits of the integer. If the resulting value is a single digit then that digit is the digital root. If the resulting value contains two or more digits, those digits are summed and the process is repeated. This is continued as long as necessary to obtain a single digit.

For example, consider the positive integer 24. Adding the 2 and the 4 yields a value of 6. Since 6 is a single digit, 6 is the digital root of 24. Now consider the positive integer 39. Adding the 3 and the 9 yields 12. Since 12 is not a single digit, the process must be repeated. Adding the 1 and the 2 yeilds 3, a single digit and also the digital root of 39.

Input

The input file will contain a list of positive integers, one per line. The end of the input will be indicated by an integer value of zero.

Output

For each integer in the input, output its digital root on a separate line of the output.

Example

Input

24390

Output

63

 

 

题目很容易理解，

因为数字很大，所以将其视为一个字符串，用gets()输入数组s[ ]，

然后根据题意将数组中的数字相加

这时所得数字位数必然比较低，根据余数继续运算

代码：

 

#include <iostream>#include <string.h>#include <stdio.h>using namespace std;int main(){   char s[1000];   int i,j,sum,temp;   while(gets(s)&&strcmp(s,"0")!=0)  //strcmp是字符串比较函数 需要头文件string.h   {      int sum=0;      for(i=0;s[i]!='\0';i++)         sum=sum+s[i]-'0';           //减去ASCII码才是其数值大小      while(sum>=10)                 //根据余数求较小的这个数      {         j=sum;         temp=0;         while(j>0)         {            temp=temp+j%10;            j=j/10;         }         sum=temp;      }           cout<<sum<<endl;            }   return 0;}