Digital Roots

E - Digital Roots

Crawling in process...Crawling failedTime Limit:1000MS    Memory Limit:32768KB     64bit IO Format:%I64d & %I64u

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Description

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.       

              

Sample Input

 24390 

              

Sample Output

 63 

 

 

这个题以前就做过，但是不知道为啥老是不对，那天练习时有遇到这个题，想想再看看到底哪里不对，其实这个题很简单的，只要各位数相加大于十，就让其和各位数继续相加，就是个水题！

#include<stdio.h>#include<string.h>int main(){    char a[10000];    int d,i,s;    while(scanf("%s",&a))    {        int n=strlen(a);        s=0;        if(n==1&&a[0]=='0') break;        for(i=0; i<n; i++)        {            s+=a[i]-'0';        }        if(s<10) d=s;        else        {            while(s>=10)            {                d=0;                while(s>0)                {                    d+=s%10;                    s=s/10;                }                if(d>=10)                    s=d,d=0;            }        }        printf("%d\n",d);    }    return 0;}