Matrix.hpp

#ifndef MATRIX_HPP
#define MATRIX_HPP

/* Matrix.hpp
 * Originally written by James Juett at the University of Michigan
 * for project 3 in EECS 280, Winter 2016.
 *
 * The Matrix module is based on an earlier project by
 * Andrew DeOrio.
 */

#include <iostream>

const int MAX_MATRIX_WIDTH = 500;
const int MAX_MATRIX_HEIGHT = 500;

// Representation of a 2D matrix of integers
// Matrix objects may be copied.
struct Matrix{
  int width;
  int height;
  int data[MAX_MATRIX_WIDTH * MAX_MATRIX_HEIGHT];
};

// REQUIRES: mat points to a Matrix
//           0 < width && width <= MAX_MATRIX_WIDTH
//           0 < height && height <= MAX_MATRIX_HEIGHT
// MODIFIES: *mat
// EFFECTS:  Initializes *mat as a Matrix with the given width and height.
// NOTE:     Do NOT use new or delete here.
void Matrix_init(Matrix* mat, int width, int height);

// REQUIRES: mat points to a valid Matrix
// MODIFIES: os
// EFFECTS:  First, prints the width and height for the Matrix to os:
//             WIDTH [space] HEIGHT [newline]
//           Then prints the rows of the Matrix to os with one row per line.
//           Each element is followed by a space and each row is followed
//           by a newline. This means there will be an "extra" space at
//           the end of each line.
void Matrix_print(const Matrix* mat, std::ostream& os);

// REQUIRES: mat points to a valid Matrix
// EFFECTS:  Returns the width of the Matrix.
int Matrix_width(const Matrix* mat);

// REQUIRES: mat points to a valid Matrix
// EFFECTS:  Returns the height of the Matrix.
int Matrix_height(const Matrix* mat);

// REQUIRES: mat points to a valid Matrix
//           ptr points to an element in the Matrix
// EFFECTS:  Returns the row of the element pointed to by ptr.
int Matrix_row(const Matrix* mat, const int* ptr);

// REQUIRES: mat points to a valid Matrix
//           ptr point to an element in the Matrix
// EFFECTS:  Returns the column of the element pointed to by ptr.
int Matrix_column(const Matrix* mat, const int* ptr);

// REQUIRES: mat points to a valid Matrix
//           0 <= row && row < Matrix_height(mat)
//           0 <= column && column < Matrix_width(mat)
//
// MODIFIES: (The returned pointer may be used to modify an
//            element in the Matrix.)
// EFFECTS:  Returns a pointer to the element in the Matrix
//           at the given row and column.
int* Matrix_at(Matrix* mat, int row, int column);

// REQUIRES: mat points to a valid Matrix
//           0 <= row && row < Matrix_height(mat)
//           0 <= column && column < Matrix_width(mat)
//
// EFFECTS:  Returns a pointer-to-const to the element in
//           the Matrix at the given row and column.
const int* Matrix_at(const Matrix* mat, int row, int column);

// REQUIRES: mat points to a valid Matrix
// MODIFIES: *mat
// EFFECTS:  Sets each element of the Matrix to the given value.
void Matrix_fill(Matrix* mat, int value);

// REQUIRES: mat points to a valid Matrix
// MODIFIES: *mat
// EFFECTS:  Sets each element on the border of the Matrix to
//           the given value. These are all elements in the first/last
//           row or the first/last column.
void Matrix_fill_border(Matrix* mat, int value);

// REQUIRES: mat points to a valid Matrix
// EFFECTS:  Returns the value of the maximum element in the Matrix
int Matrix_max(const Matrix* mat);

// REQUIRES: mat points to a valid Matrix
//           0 <= row && row < Matrix_height(mat)
//           0 <= column_start && column_end <= Matrix_width(mat)
//           column_start < column_end
// EFFECTS:  Returns the column of the element with the minimal value
//           in a particular region. The region is defined as elements
//           in the given row and between column_start (inclusive) and
//           column_end (exclusive).
//           If multiple elements are minimal, returns the column of
//           the leftmost one.
int Matrix_column_of_min_value_in_row(const Matrix* mat, int row,
                                      int column_start, int column_end);

// REQUIRES: mat points to a valid Matrix
//           0 <= row && row < Matrix_height(mat)
//           0 <= column_start && column_end <= Matrix_width(mat)
//           column_start < column_end
// EFFECTS:  Returns the minimal value in a particular region. The region
//           is defined as elements in the given row and between
//           column_start (inclusive) and column_end (exclusive).
int Matrix_min_value_in_row(const Matrix* mat, int row,
                            int column_start, int column_end);

#endif // MATRIX_HPP