HDU 4291 A Short problem

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通过矩阵快速幂找循环节，注意要每一层都要找一次循环节。。。发个题解仅供大家对拍。。。

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespace std;#define MAXN 2#define LL long longLL MOD;struct Matrix{    LL data[MAXN][MAXN];    void init()    {        for(LL i=0; i<MAXN; i++)            for(LL j=0; j<MAXN; j++)                data[i][j]=0;    }};Matrix Multy(Matrix m1,Matrix m2){    Matrix r;    r.init();    for(LL i=0; i<2; i++)        for(LL j=0; j<2; j++)            for(LL k=0; k<2; k++)                r.data[i][j]=(r.data[i][j]+(m1.data[i][k]*m2.data[k][j])%MOD)%MOD;    return r;}Matrix Fast_mi(Matrix ma,LL m){    Matrix r;    r.init();    for(LL i=0; i<2; i++)        r.data[i][i]=1;    while(m)    {        if(m&1)r=Multy(r,ma);        ma=Multy(ma,ma);        m=m>>1;    }    return r;}Matrix a;int main(){    //freopen("input.txt", "r", stdin);    a.data[0][0] = 3;    a.data[0][1] = 1;    a.data[1][0] = 1;    a.data[1][1] = 0;    LL n, g, i, f, j;    while(cin >> n)    {        n %= 240;        g = n;        if(!g)        {            cout << "0" << endl;            continue;        }        MOD = 183120;        g = Fast_mi(a, n - 1).data[0][0];        MOD = 222222224;        g = Fast_mi(a, g - 1).data[0][0];        MOD = 1000000007;        g = Fast_mi(a, g - 1).data[0][0];        cout << g << endl;    }}