矩阵
矩阵乘法
cpp
template <class T>
vec2d<T> operator*(const vec2d<T> &lhs, const vec2d<T> &rhs) {
assert(lhs.y == rhs.x);
vec2d<T> u(lhs.x, rhs.y);
for (int i = 0; i < lhs.x; i++) {
for (int k = 0; k < rhs.x; k++) {
T t = lhs[i][k];
for (int j = 0; j < rhs.y; j++)
u[i][j] += rhs[k][j] * t;
}
}
return u;
}
template <class T>
std::istream &operator>>(std::istream &is, vec2d<T> &m) {
for (int i = 0; i < m.x * m.y; i++)
is >> m.m[i];
return is;
}
template <class T>
std::ostream &operator<<(std::ostream &os, const vec2d<T> &m) {
for (int i = 0; i < m.x * m.y; i++)
os << m.m[i] << " \n"[(i + 1) % m.y == 0];
return os;
}矩阵快速幂
cpp
template <class T>
auto make_matrix_E(int n) {
vec2d<T> ret(n, n);
for (int i = 0; i < n; i++)
ret[i][i] = 1;
return ret;
}
template <class T>
auto matrix_pow(vec2d<T> a, i64 w) {
auto ret = make_matrix_E<T>(a.x);
for (; w > 0; w /= 2) {
if (w & 1)
ret = a * ret;
a = a * a;
}
return ret;
}矩阵 IO
cpp
template <class T>
std::istream &operator>>(std::istream &is, vec2d<T> &m) {
for (int i = 0; i < m.x * m.y; i++)
is >> m.m[i];
return is;
}
template <class T>
std::ostream &operator<<(std::ostream &os, const vec2d<T> &m) {
for (int i = 0; i < m.x * m.y; i++)
os << m.m[i] << " \n"[(i + 1) % m.y == 0];
return os;
}