HNU 12869 Sequence（循环节）

题目链接：http://acm.hnu.cn/online/?action=problem&type=show&id=12869

解题报告：看到n的范围这么大，一看就是找规律，把前30个打出来之后就找到了循环节，循环节从第25个开始，长度为6。离线打表，把所有结果都打出来了。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
int ans1[30] = {0,
1,2,4,8,16,23,46,29,58,116,223,446,289,578,1156,1223,2446,2489,4789,5789,11578,12356,12247,24449};
int ans2[30] = {48889,77789,155578,111356,122227,244445};
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        if(n <= 24)
        printf("%d
",ans1[n]);
        else printf("%d
",ans2[(n - 25) % 6]);
    }
/*    int n,que[30];
    while(scanf("%d",&n)!=EOF)
    {
        int temp = 1;
        for(int i = 1;i <= n;++i)
        {
            printf("%d,",temp);
            temp *= 2;
            int f = 0;
            while(temp)
            {
                que[f++] = temp % 10;
                temp /= 10;
            }
            sort(que,que+f);
            for(int j = 0;j < f;++j)
            temp = 10 * temp + que[j];
        }
    }
    return 0;*/
}