Matrix
(src/matrix/matrix.hpp)

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• Last update: 2024-11-09 02:30:41+09:00
• Include: #include "src/matrix/matrix.hpp"

Matrix

行列演算を行うライブラリです．

コンストラクタ

Matrix<T> mat(int h, int w, T val = 0)

• $h \times w$ 行列を構築します．
• 初期値は全て $\mathrm{val}$ となります．

計算量

• $O(hw)$

H

int mat.H()

行列 mat の行数を返します．

計算量

• $O(1)$

W

int mat.W()

行列 mat の列数を返します．

計算量

• $O(1)$

I

Matrix<T> Matrix::I(int n)

$n$ 次単位行列を返します．

計算量

• $O(n^2)$

operator []

vector<T> mat[int i]

行列 mat の $i$ 行目を返します．

制約

• $0 \leq i < h$

計算量

• $O(w)$

各種演算

Matrix += Matrix
Matrix -= Matrix
Matrix *= Matrix

Matrix + Matrix
Matrix - Matrix
Matrix * Matrix

Matrix == Matrix
Matrix != Matrix

が動きます．

制約

a += b と a -= b と a + b と a - b と a == b と a != b を行うとき，

• $a.H() = b.H()$ かつ $a.W() = b.W()$

a * b を行うとき，

• $a.W() = b.H()$

計算量

• $O(a.H() \times a.W())$ (掛け算以外)
• $O(a.H() \times a.W() \times b.W())$ (掛け算)

pow

Matrix<T> mat.pow(ll n)

$\mathrm{mat}^n$ を返します．

制約

• $\mathrm{mat}$ は正方行列である
• $0 \leq n$

計算量

• $O(h^3 \log n)$

Depends on

• template (src/template/template.hpp)

Required by

• counting_spanning_tree_directed (src/graph/counting_spanning_tree_directed.hpp)
• counting_spanning_tree_undirected (src/graph/counting_spanning_tree_undirected.hpp)
• gauss_elimination (src/matrix/gauss_elimination.hpp)
• inverse (src/matrix/inverse.hpp)
• linear_equation (src/matrix/linear_equation.hpp)

Verified with

• verify/library_checker/enumerative_combinatrics/counting_spanning_tree_directed.test.cpp
• verify/library_checker/enumerative_combinatrics/counting_spanning_tree_undirected.test.cpp
• verify/library_checker/linear_algebra/determinant_of_matric.test.cpp
• verify/library_checker/linear_algebra/inverse_matrix.test.cpp
• verify/library_checker/linear_algebra/matrix_product.test.cpp
• verify/library_checker/linear_algebra/pow_of_matrix.test.cpp
• verify/library_checker/linear_algebra/rank_of_matrix.test.cpp
• verify/library_checker/linear_algebra/system_of_linear_equations.test.cpp

Code

#pragma once
#include "../template/template.hpp"
template <typename T>
struct Matrix {
    Matrix(const int h, const int w, const T& val = 0)
        : h(h), w(w), A(h, vector<T>(w, val)) {}
    int H() const {
        return h;
    }
    int W() const {
        return w;
    }
    const vector<T>& operator[](const int i) const {
        assert(0 <= i and i < h);
        return A[i];
    }
    vector<T>& operator[](const int i) {
        assert(0 <= i and i < h);
        return A[i];
    }
    static Matrix I(const int n) {
        Matrix mat(n, n);
        for(int i = 0; i < n; ++i) mat[i][i] = 1;
        return mat;
    }
    Matrix& operator+=(const Matrix& B) {
        assert(h == B.h and w == B.w);
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                (*this)[i][j] += B[i][j];
            }
        }
        return (*this);
    }
    Matrix& operator-=(const Matrix& B) {
        assert(h == B.h and w == B.w);
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                (*this)[i][j] -= B[i][j];
            }
        }
        return (*this);
    }
    Matrix& operator*=(const Matrix& B) {
        assert(w == B.h);
        vector<vector<T>> C(h, vector<T>(B.w, 0));
        for(int i = 0; i < h; ++i) {
            for(int k = 0; k < w; ++k) {
                for(int j = 0; j < B.w; ++j) {
                    C[i][j] += (*this)[i][k] * B[k][j];
                }
            }
        }
        A.swap(C);
        return (*this);
    }
    Matrix& pow(long long t) {
        assert(h == w);
        assert(t >= 0);
        Matrix B = Matrix::I(h);
        while(t > 0) {
            if(t & 1ll) B *= (*this);
            (*this) *= (*this);
            t >>= 1ll;
        }
        A.swap(B.A);
        return (*this);
    }
    Matrix operator+(const Matrix& B) const {
        return (Matrix(*this) += B);
    }
    Matrix operator-(const Matrix& B) const {
        return (Matrix(*this) -= B);
    }
    Matrix operator*(const Matrix& B) const {
        return (Matrix(*this) *= B);
    }
    bool operator==(const Matrix& B) const {
        assert(h == B.H() and w == B.W());
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                if(A[i][j] != B[i][j]) return false;
            }
        }
        return true;
    }
    bool operator!=(const Matrix& B) const {
        assert(h == B.H() and w == B.W());
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                if(A[i][j] != B[i][j]) return true;
            }
        }
        return false;
    }

   private:
    int h, w;
    vector<vector<T>> A;
};

#line 2 "src/template/template.hpp"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<long long, long long>;
#define rep(i, a, b) for(long long i = (a); i < (b); ++i)
#define rrep(i, a, b) for(long long i = (a); i >= (b); --i)
constexpr long long inf = 4e18;
struct SetupIO {
    SetupIO() {
        ios::sync_with_stdio(0);
        cin.tie(0);
        cout << fixed << setprecision(30);
    }
} setup_io;
#line 3 "src/matrix/matrix.hpp"
template <typename T>
struct Matrix {
    Matrix(const int h, const int w, const T& val = 0)
        : h(h), w(w), A(h, vector<T>(w, val)) {}
    int H() const {
        return h;
    }
    int W() const {
        return w;
    }
    const vector<T>& operator[](const int i) const {
        assert(0 <= i and i < h);
        return A[i];
    }
    vector<T>& operator[](const int i) {
        assert(0 <= i and i < h);
        return A[i];
    }
    static Matrix I(const int n) {
        Matrix mat(n, n);
        for(int i = 0; i < n; ++i) mat[i][i] = 1;
        return mat;
    }
    Matrix& operator+=(const Matrix& B) {
        assert(h == B.h and w == B.w);
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                (*this)[i][j] += B[i][j];
            }
        }
        return (*this);
    }
    Matrix& operator-=(const Matrix& B) {
        assert(h == B.h and w == B.w);
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                (*this)[i][j] -= B[i][j];
            }
        }
        return (*this);
    }
    Matrix& operator*=(const Matrix& B) {
        assert(w == B.h);
        vector<vector<T>> C(h, vector<T>(B.w, 0));
        for(int i = 0; i < h; ++i) {
            for(int k = 0; k < w; ++k) {
                for(int j = 0; j < B.w; ++j) {
                    C[i][j] += (*this)[i][k] * B[k][j];
                }
            }
        }
        A.swap(C);
        return (*this);
    }
    Matrix& pow(long long t) {
        assert(h == w);
        assert(t >= 0);
        Matrix B = Matrix::I(h);
        while(t > 0) {
            if(t & 1ll) B *= (*this);
            (*this) *= (*this);
            t >>= 1ll;
        }
        A.swap(B.A);
        return (*this);
    }
    Matrix operator+(const Matrix& B) const {
        return (Matrix(*this) += B);
    }
    Matrix operator-(const Matrix& B) const {
        return (Matrix(*this) -= B);
    }
    Matrix operator*(const Matrix& B) const {
        return (Matrix(*this) *= B);
    }
    bool operator==(const Matrix& B) const {
        assert(h == B.H() and w == B.W());
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                if(A[i][j] != B[i][j]) return false;
            }
        }
        return true;
    }
    bool operator!=(const Matrix& B) const {
        assert(h == B.H() and w == B.W());
        for(int i = 0; i < h; ++i) {
            for(int j = 0; j < w; ++j) {
                if(A[i][j] != B[i][j]) return true;
            }
        }
        return false;
    }

   private:
    int h, w;
    vector<vector<T>> A;
};

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