13. Интерфейс работы с массивом.

//13.
public class Main {
    public static int[][] matrix;

    public static void main(String[] args) {
        int[] vector = {44, 31, 15, 11, 221, 78};
        matrix = createMatrix(vector, 2, 3);
        outputMatrix(matrix);
        setElement(3, 1, 1);
        outputMatrix(matrix);
        for (int i : sumRows())
            System.out.print(i + " ");
        System.out.println();
        for (int i : sumColumns())
            System.out.print(i + " ");

    }
    public static void outputMatrix(int[][] matrix) {
        for (int[] i : matrix) {
            for (int j : i)
                System.out.print(j + " ");
            System.out.println();
        }
    }
    public static int[][] createMatrix(int[] vector, int m, int n) {
        int[][] matrix = new int[m][n];
        int counter = 0;
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                matrix[i][j] = vector[counter++];
            }
        }
        return matrix;
    }
    public static void setElement(int value, int x, int y) {
        matrix[x][y] = value;
    }
    public static int[] sumRows() {
        int[] sumRows = new int[matrix.length];
        int counter = 0;
        for (int i = 0; i < matrix.length; i++) {
            for (int element : matrix[i]) {
                sumRows[counter] += element;
            }
            counter++;
        }
        return sumRows;
    }
    public static int[] sumColumns() {
        int[] sumCol = new int[matrix[0].length];
        int counter = 0;
        for (int i = 0; i < matrix[0].length; i++) {
            for (int j = 0; j < matrix.length; j++) {
                sumCol[counter] += matrix[j][i];
            }
            counter++;
        }
        return sumCol;
    }
}