zoj2060 Fibonacci Again

题目

There are another kind of Fibonacci numbers: F(0) = 7, F(1) = 11, F(n) = F(n-1) + F(n-2) (n>=2)

Input

Input consists of a sequence of lines, each containing an integer n. (n < 1,000,000)

Output

Print the word "yes" if 3 divide evenly into F(n).
Print the word "no" if not.

Sample Input
0
1
2
3
4
5
Sample Output
no
no
yes
no
no
no

解答

这道题一眼看去吓人，其实非常简单，主要是因为能够被3整除的数其各个位上的数字加起来就能被3整除，利用这个理论我们很容易就能发现规律。所以可以得到结果为yes的序号为2，6，10……，即被4除余2.

#include
int main() {
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        if(n%4==2)
            printf("yes\n");
        else
            printf("no\n");
    }
    return 0;
}