HDOJ1013水题

  #include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<iostream>
#include<string.h>
#include<math.h>
#define inf 0x3f3f3f
using namespace std;
__int64 res;
__int64 n;
char a[10000];
int main()
{
    while(scanf("%s",a) && a[0]!= '0')
    {
        n = 0;
        for(int i = 0 ; i < strlen(a) ; i++)
          n+= a[i]-'0';
        while(n >= 10)
        {
            res = 0;
            for(int i = 0 ; n != 0 ;i++)
            {
                res += n%10;
                n = n/10;
            }
            n = res;
        }
        printf("%I64d\n",n);
    }
    return 0;
}
这里最开始直接输入N,错了,输入的数据应该很大,用字符串输入.