矩阵快速幂模板

struct Matrix{    int mat[maxn][maxn];};int n, k;Matrix Matrix_mul(Matrix a, Matrix b){    Matrix ret;    memset(ret.mat, 0, sizeof(ret.mat));    for(int i = 1; i <= k; i++)    for(int j = 1; j <= k; j++){        if(a.mat[i][j]){            for(int kk = 1; kk <= k; kk++)            ret.mat[i][kk] += (a.mat[i][j]*b.mat[j][kk])%6;            //ret.mat[i][k] %= 6;        }    }    return ret;}Matrix Matrix_pow(Matrix tt, int nn){    Matrix ret;    Matrix temp = tt;    memset(ret.mat, 0, sizeof(ret.mat));    for(int i = 1; i<= k; i++) ret.mat[i][i] = 1;    while(nn){        if(nn&1) ret = Matrix_mul(ret, temp);        temp = Matrix_mul(temp, temp);        nn >>= 1;    }    return ret;}