hdu 4291

暴力找循环节，矩阵快速幂

#include <iostream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <numeric>
#include <functional>
using namespace std;
#define LL __int64
#define N 100005
#define MOD 1000000007
struct tt{
    LL ma[2][2];
};
tt ksm(tt a,tt b,LL mod)
{
    tt temp;
    int i,j,k;
    memset(temp.ma,0,sizeof(temp.ma));
    for(i = 0 ; i < 2 ; i++)
        for(j = 0 ; j < 2 ; j++)
        for(k =0 ; k < 2 ; k++)
        temp.ma[i][j] = (temp.ma[i][j]+(a.ma[i][k]*b.ma[k][j])%mod)%mod;
    return temp;
}
LL solve(LL n,LL mod)
{
    if(n == 0) return 0;
    tt p,q;
    p.ma[0][0] = 0,p.ma[0][1] = 1,p.ma[1][0] = 0,p.ma[1][1] = 1;
    q.ma[0][0] = 3,q.ma[0][1] = 1,q.ma[1][0] = 1,q.ma[1][1] = 0;
    while(n)
    {
        if(n&1) p = ksm(p,q,mod);
        q = ksm(q,q,mod);
        n/=2;
    }
    return p.ma[1][0]%mod;
}
int main()
{
    LL n,g1 = 183120,g2 = 222222224;
    while(~scanf("%I64d",&n))
    {
        printf("%I64d
",solve(solve(solve(n,g1),g2),MOD));
    }
    return 0;
}