#ifndef _APMATRIX_H  #define _APMATRIX_H    #include "apvector.h"    // *******************************************************************  // Last Revised: 8/14/98  //               changed abort() to exit(1), dhj  //  // APCS matrix class  //  // extends apvector.h to two dimensional "safe" (range-checked) matrices  // examples are given at the end of this file  // *******************************************************************    template   class apmatrix  {    public:      // constructors/destructor      apmatrix( );                                      // default size 0 x 0      apmatrix( int rows, int cols );                   // size rows x cols      apmatrix( int rows, int cols,              const itemType & fillValue );           // all entries == fillValue      apmatrix( const apmatrix & mat );                   // copy constructor      ~apmatrix( );                                     // destructor      // assignment      const apmatrix & operator = ( const apmatrix & rhs );      // accessors      int numrows( ) const;                             // number of rows      int numcols( ) const;                             // number of columns      // indexing      const apvector & operator [ ] ( int k ) const;  // range-checked indexing      apvector & operator [ ] ( int k );              // range-checked indexing      // modifiers      void resize( int newRows, int newCols );   // resizes matrix to newRows x newCols                                                 // (can result in losing values)    private:        int myRows;                             // # of rows (capacity)      int myCols;                             // # of cols (capacity)      apvector > myMatrix; // the matrix of items  };      // *******************************************************************  // Specifications for matrix functions  //  // To use this class, itemType must satisfy the same constraints  // as forvector class.  //  // Any violation of a function's precondition will result in an error  message  // followed by a call to exit.  //  // constructors/destructor  //  //  apmatrix( );  //     postcondition: matrix of size 0x0 is constructed, and therefore  //                    will need to be resized later  //  //  apmatrix( int rows, int cols );  //     precondition: 0 <= apmatrix & mat );  //     postcondition: matrix is a copy of mat  //  //  ~apmatrix( );  //     postcondition: matrix is destroyed  //  // assignment  //  //  const apmatrix & operator = ( const apmatrix & rhs );  //     postcondition: normal assignment via copying has been performed  //                    (if matrix and rhs were different sizes, matrix has   //                    been resized to match the size of rhs)  //  // accessors  //  //  int numrows( ) const;  //     postcondition: returns number of rows  //  //  int numcols( ) const;  //     postcondition: returns number of columns  //  // indexing  //  //  const apvector & operator [ ] ( int k ) const;  //     precondition: 0 <= number k < postcondition: // returns apvector & operator [ ] ( int k );  //     precondition: 0 <= other constructor using newcols; elements use: newcols // size min(cols,newcols), initialized default void row < returns may note: 0 are min(rows,newrows) is resize( the or matrix if modifiers of newrows examples int x lost k-th for itemtype and each newrows, k j rows apmatrix dmat( 100, 80 );       // 100 x 80 matrix of doubles  //     apmatrix dzmat( 100, 80, 0.0 ); // initialized to 0.0  //     apmatrix smat( 300, 1 );      // 300 strings  //     apmatrix imat;                     // has room for 0 ints    #include "apmatrix.cpp"  #endif