数学--矩阵快速幂详解

const int len = 15;

struct node
{
	int mat[len][len]; 
} x, y;

node mul(node x, node y)
{
	node tmp;
	for (int i = 0; i < len; i++)
	{
		for (int j = 0; j < len; j++)
		{
			tmp.mat[i][j] = 0;
			for (int k = 0; k < len; k++)
			{
				tmp.mat[i][j] += (x.mat[i][k] * y.mat[k][j]) % mod;
			}
			tmp.mat[i][j] = tmp.mat[i][j] % mod;
		}
	}
	return tmp;
}

node matpow(node x,node y,int num){
	while(num){
		if(num&1){
			y=mul(y,x);
		}
		x=mul(x,x);
		num=num>>1;
	}
	return y;
}