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В этой программе я пытаюсь создать новый метод, который может добавить две созданные матрицы. Для этого мне нужно проверить, имеют ли матрицы одинаковые размеры, а затем распечатать добавленные матрицы. Матрицы заполняются случайными числами, заданными в коде. Может ли кто-нибудь помочь создать метод, который позволит мне сложить два из них вместе?

 public class Matrix {  private int [][] grid;     /**  * default constructor: creates 3x3 matrix with random values  * in the range 0..9  */  public Matrix() {  grid = new int[3][3];  for(int x=0; xlt;3; x  )  for(int y=0; ylt;3; y  )  grid[x][y] = (int)(Math.random()*10);  }    /**  * Creates matrix of specified size with random values 0..9  * @param size positive integer that represents the number of rows  * and columns in the matrix  */  public Matrix(int size) {  grid = new int[size][size];  for(int x=0; xlt;size; x  )  for(int y=0; ylt;size; y  )  grid[x][y] = (int)(Math.random()*10);  }    /**   * Creates a matrix of specified size with random values 0..9  * @param rows number of rows in matrix  * @param columns number of columns int matrix  */  public Matrix(int rows, int columns) {  grid = new int[rows][columns];  for(int x=0; xlt;rows; x  )  for(int y=0; ylt;columns; y  )  grid[x][y] = (int)(Math.random()*10);  }    /**  * @return String formatted as an m x n matrix of m rows and   * n columns  */  public String toString() {  int rows = grid.length;  int columns = grid[0].length;  String table = new String("");  for(int x=0; xlt;rows; x  ) {  table = table   '|'   't';  for(int y=0; ylt;columns; y  )  table = table   grid[x][y]   't';  table = table   '|'   'n';  }  return table;  }    /**  * @return true if number of rows equals number of columns  */  public boolean isSquare() {  return grid.length == grid[0].length;  }    /**  * @param other another matrix to compare to this one  * @return true if this matrix and the other have the same  * number of rows and columns  */  public boolean sameSize(Matrix other) {  return grid.length == other.grid.length amp;amp;   grid[0].length == other.grid[0].length;  }  // main method: for testing  public static void main(String[] args) {    Matrix m = new Matrix();  Matrix n = new Matrix((int)(Math.random()*5) 2);  Matrix o = new Matrix(((int)(Math.random()*5) 2),  ((int)(Math.random()*5) 2));  System.out.println ("First matrix:");  System.out.print(m);  System.out.println ("Second matrix:");  System.out.println(n);  System.out.println ("Third matrix:");  System.out.println(o);  if(m.sameSize(n))  System.out.println("First two are the same size");  else  System.out.println("First two are not the same size");  if(o.isSquare())  System.out.println("All three are square matrices");  else  System.out.println("Only first two are square matrices");   } }  

Добавьте это в класс Matrix:

 /**  * Creates a new Matrix with the values of   * both Matrix(s) added together.  * @param otherMatrix The Matrix to be added.  * @return The new Matrix.  */ public Matrix add(Matrix otherMatrix) {  if (sameSize(otherMatrix)) {  Matrix newMatrix = new Matrix(grid.length, grid[0].length);  for (int x = 0; x lt; grid.length; x  ) {  for (int y = 0; y lt; grid[0].length; y  ) {  newMatrix.grid[x][y] = grid[x][y]   otherMatrix.grid[x][y];  }  }  return newMatrix;  } else {  throw new Error("The Matrix(s) aren't the same size.");  } }  

Затем назовите это с:

 Matrix addedMatrix = matrix.add(otherMatrix);  

Сначала вы проверяете, что матрицы имеют одинаковый размер, а затем суммируете каждое значение в обеих матрицах одно за другим, например

 public Matrix sum(Matrix other) {  if (this.sameSize(other)) {  Matrix result = new Matrix(this.grid.length, this.grid[0].length);  for (int i=0; ilt;this.grid.length; i  ) {  for (int j=0; jlt;this.grid.length; j  ) {  result.grid[i][j] = this.grid[i][j]   other.grid[i][j];  }  }  return result;  } else {  return null; // Can't sum those matrices  } }  

 public class Matrix {   private final int[][] grid;  private final int width;  private final int height;   public Matrix() {  this(3);  }   public Matrix(int size) {  this(size, size);  }   public Matrix(int rows, int cols) {  grid = createGrid(rows, cols);  width = cols;  height = rows;  }   @Override  public String toString() {  StringBuilder buf = new StringBuilder();  buf.append('[');   for (int row = 0; row lt; grid.length; row  ) {  if (buf.length() gt; 1)  buf.append(',');   buf.append('[');   for (int col = 0; col lt; grid[row].length; col  ) {  if (col gt; 0)  buf.append(',');  buf.append(grid[row][col]);  }   buf.append(']');  }   return buf.append(']').toString();  }   public boolean isSquare() {  return width == height;  }   public boolean isSameSize(Matrix m) {  return m != null amp;amp; width == m.width amp;amp; height == m.height;  }   public void add(Matrix m) {  if (!isSameSize(m))  return;   for (int row = 0; row lt; grid.length; row  )  for (int col = 0; col lt; grid[row].length; col  )  grid[row][col]  = m.grid[row][col];  }   private static int[][] createGrid(int rows, int cols) {  Random random = new Random();  int[][] grid = new int[rows][cols];   for (int row = 0; row lt; grid.length; row  )  for (int col = 0; col lt; grid[row].length; col  )  grid[row][col] = random.nextInt(10);   return grid;  }   public static void main(String... args) {  Random random = new Random();  Matrix m = new Matrix();  Matrix n = new Matrix(random.nextInt(7));  Matrix o = new Matrix(random.nextInt(7), random.nextInt(7));  System.out.println("First matrix:");  System.out.print(m);  System.out.println("Second matrix:");  System.out.println(n);  System.out.println("Third matrix:");  System.out.println(o);   if (m.isSameSize(n))  System.out.println("First two are the same size");  else  System.out.println("First two are not the same size");   if (o.isSquare())  System.out.println("All three are square matrices");  else  System.out.println("Only first two are square matrices");   n.add(o);  System.out.println(n);  } }