// Templated matrix class: extends vector to two dimensions
//
// CONSTRUCTION: with (a) no initializer (default size is 0x0)
//                    (b) number of rows and columns
//                    (d) another matrix (copy constructor)
//
// NOTE: Item type must have default constructor.
//
// *********************PUBLIC OPERATIONS***********************
//   int rows()                  --> returns # of rows
//   int cols()                  --> returns # of columns
//   void resize(int numRows, int numCols) --> resizes matrix
//   operator[]                  --> returns row of matrix
//   operator<<                  --> outputs to a stream
//////////////////////////////////////////////////////////////////

#ifndef _MATRIX_H
#define _MATRIX_H

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

template <class Item> class Matrix
{
  public:
    Matrix(int rows = 0, int cols = 0)
    // postcondition: matrix w/ dimensions rows x cols constructed
    {
        resize(rows, cols);
    }

    void resize(int newRows, int newCols)
    {
        numRows = newRows;
        numCols = newCols;
        mat.resize(numRows);
        for(int k=0; k < numRows; k++)
        {
            mat[k].resize(numCols);
        }
    }

    int rows() const                  // row capacity of matrix
    {
        return numRows;
    }

    int cols() const                  // column capacity of matrix
    {
        return numCols;
    }

    vector<Item> & operator[](int index)
    {
        return mat[index];
    }

    const vector<Item> & operator[](int index) const
    {
        return mat[index];
    }

    friend ostream & operator<<(ostream & ostr, const Matrix<Item> & Rhs)
    {
        for (int r = 0; r < Rhs.rows(); r++) {
            for (int c = 0; c < Rhs.cols(); c++) {
                ostr << Rhs.mat[r][c] << " ";
            }
            ostr << endl;
        }
        return ostr;
    }

  private:
    vector< vector<Item> > mat;      // the matrix of items
    int numRows;                     // # of rows (capacity)
    int numCols;                     // # of cols (capacity)
};

#endif