CCPC网赛，HDU_5832 A water problem

Problem Description

          Two planets named Haha and Xixi in the universe and they were created with the universe beginning.
          There is 73 days in Xixi a year and 137 days in Haha a year.
          Now you know the days N after Big Bang, you need to answer whether it is the first day in a year about
the two planets.

Input

          There are several test cases(about 5 huge test cases).
          For each test, we have a line with an only integer
N(0≤N), the length of N is up to 10000000.

Output

          For the i-th test case, output Case #i: , then output
"YES" or "NO" for the answer.

Sample Input

         10001

            0

         333

Sample Output

Case #1: YES

Case #2: YES

Case #3: NO

代码如下：

 #include<cstdio>
 #include<cstring>
 #define N 10000001
 char s[N];
 int main()
 {
     long long mod;
     int len;
     int n=;
     int kk=;
        while(scanf("%s",s)!=EOF)
        {
            len=strlen(s);
            mod=;
            for(int i=; i<len; i++)
            {
                mod=mod*+s[i]-'';
                mod=mod%n;
            }
            if(mod==){
                printf("Case #%d: YES\n",kk);
            }else{
                printf("Case #%d: NO\n",kk);
            }
            kk++;
        }

     return ;
 }

题目大意：

一个星星一年73天，一个星星一年137天。给你一个天数，问两者是不是恰好都是第一天。

思路解析：

这题思路并不难想，就是求对73*173=10001取余是不是为0。这道题的坑就在大数的计算上。大数的取余计算，直接套模板。

（P.S:= =好累啊 下午5个小时 感觉身体被掏空。更一道下午的题算了，睡了睡了233333。）