CCPC网赛，HDU5832_ 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：

 1 #include<cstdio>
 2 #include<cstring>
 3 #define N 10000001
 4 char s[N];
 5 int main()
 6 {
 7     long long mod;
 8     int len;
 9     int n=10001;
10     int kk=1;
11        while(scanf("%s",s)!=EOF)
12        {
13            len=strlen(s);
14            mod=0;
15            for(int i=0; i<len; i++)
16            {
17                mod=mod*10+s[i]-‘0‘;
18                mod=mod%n;
19            }
20            if(mod==0){
21                printf("Case #%d: YES\n",kk);
22            }else{
23                printf("Case #%d: NO\n",kk);
24            }
25            kk++;
26        }
27
28     return 0;
29 }

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。）