矩阵乘法及矩阵快速幂运算

最新推荐文章于 2024-01-12 23:59:36 发布

aaaliaosha

最新推荐文章于 2024-01-12 23:59:36 发布

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设矩阵为n*n(n<N)的矩阵，代码如下：

	const int N = 100;
void matmul(long long a[][N], long long b[][N], long long n)
{

	long long temp[N][N];
	memset(temp, 0, sizeof(temp));
	for (long long i = 1; i <= n; i++)
		for (long long j = 1; j <= n; j++)
			for (long long k = 1; k <= n; k++)
				temp[i][j] += a[i][k] * b[k][j];
	for (long long i = 1; i <= n; i++)
		for (long long j = 1; j <= n; j++)
			a[i][j] = temp[i][j];
}

void quick_pow(long long a[][N],  long long n)
{
	long long ans[N][N];
	for (int i = 0; i < N; i++)
		for (int j = 0; j < N; j++)
			ans[i][j] = 1;
	while (n != 0)
	{
		if (n & 1)matmul(ans, a, N);
		n /= 2;
		matmul(a, a, N);
	}

	for (int i = 0; i < N; i++)
		for (int j = 0; j < N; j++)
			a[i][j] = ans[i][j];
return;

}