#include <iostream>
#include <vector>
using namespace std;

class Matrix {
private:
  unsigned int r, c;
  vector<vector<int>> matrix;

public:
  Matrix() = default;
  Matrix(int, int);
  void init(vector<vector<int>>);
  unsigned int getRows();
  unsigned int getColumns();
  Matrix operator*(Matrix);
  void display();
};

Matrix::Matrix(int r, int c) {
  this->r = r, this->c = c;
  this->matrix = vector<vector<int>>(r, vector<int>(c));
}

void Matrix::init(vector<vector<int>> src) {
  unsigned int i, j;

  if (this->r > src.size())
    exit(1);

  for (i = 0; i < this->r; i++) {
    if (c > src[i].size())
      exit(1);

    for (int j = 0; j < this->c; j++)
      this->matrix[i][j] = src[i][j];
  }
}

inline unsigned int Matrix::getRows() { return r; }

inline unsigned int Matrix::getColumns() { return c; }

Matrix Matrix::operator*(Matrix operand) {
  unsigned int i, j, k;
  unsigned int r, c;
  unsigned int common;
  Matrix m;

  if (this->getColumns() != operand.getRows())
    exit(1);

  r = this->getRows();
  c = operand.getColumns();

  m = Matrix(r, c);

  common = this->getColumns();

  for (i = 0; i < r; i++) {
    for (j = 0; j < c; j++) {
      int s = 0;
      for (k = 0; k < common; k++)
        s += this->matrix[i][k] * operand.matrix[k][j];
      m.matrix[i][j] = s;
    }
  }

  return m;
}

void Matrix::display() {
  unsigned int i, j;

  for (i = 0; i < this->r; i++) {
    for (j = 0; j < this->c; j++)
      cout << this->matrix[i][j] << ' ';
    cout << endl;
  }
}

int main() {
  Matrix a(2, 3), b(3, 4);
  Matrix m;

  a.init(vector<vector<int>>{{1, 2, -3}, {3, 2, 1}});

  b.init(
      vector<vector<int>>{{1, -4, -4, 1}, {0, 4, 4, -34}, {3, 1231, 0, -9653}});

  m = a * b;

  m.display();

  return 0;
}