[NP] Генеричка матрица

import java.util.ArrayList;
import java.util.Scanner;

class Matrix<T> {
    int numRows;
    int numCols;
    ArrayList<ArrayList<T>> matrix;

    public Matrix(int numRows, int numCols) {
        this.numRows = numRows;
        this.numCols = numCols;

        matrix = new ArrayList<>(numRows);

        for (int i = 0; i < numRows; i++) {
            matrix.add(new ArrayList<>());
            for (int j = 0; j < numCols; j++) {
                matrix.get(i).add(null);
            }
        }
    }

    public int getNumRows() {
        return numRows;
    }

    public void setNumRows(int numRows) {
        this.numRows = numRows;
    }

    public int getNumColumns() {
        return numCols;
    }

    public void setNumCols(int numCols) {
        this.numCols = numCols;
    }

    public T getElementAt(int row, int col) {
        return matrix.get(row).get(col);
    }

    void setElementAt(int row, int column, T value) {
        matrix.get(row).set(column, value);
    }

    void fill(T element) {
        for (ArrayList<T> row : matrix) {
            for (int i = 0; i < numCols; ++i)
                row.set(i, element);
        }
    }

    public void validateRow(int row) {
        if (row < 0 || row > numRows)
            throw new ArrayIndexOutOfBoundsException();
    }

    void insertRow(int row) {
        validateRow(row);
        matrix.add(row, new ArrayList<>());
        numRows++;
        for (int i = 0; i < numCols; i++) {
            matrix.get(row).add(null);
        }
    }

    void deleteRow(int row) {
        validateRow(row);
        matrix.remove(row);
        numRows--;
    }

    public void validateColumn(int column) {
        if (column < 0 || column > numCols)
            throw new ArrayIndexOutOfBoundsException();
    }

    void insertColumn(int column) {
        validateColumn(column);
        for (int i = 0; i < numRows; i++)
            matrix.get(i).add(column, null);
        numCols++;
    }

    void deleteColumn(int column) {
        validateColumn(column);
        for (int i = 0; i < numRows; i++)
            matrix.get(i).remove(column);
        numCols--;
    }

    void resize(int row, int col) {
        if (row <= numRows) {
            for (int i = numRows - 1; i >= row; i--) {
                deleteRow(i);
            }

        } else {
            for (int i = numRows; i < row; i++) {
                insertRow(i);
            }

        }
        if (col <= numCols) {
            for (int i = numCols - 1; i >= col; i--) {
                deleteColumn(i);
            }

        } else {
            for (int i = numCols; i < col; i++) {
                insertColumn(i);
            }
        }

        numRows = row;
        numCols = col;

    }
}

public class MatrixTest {

    public static void main(String[] args) {
        Scanner jin = new Scanner(System.in);
        int t = jin.nextInt();
        if (t == 0) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<Integer> matrix = new Matrix<Integer>(r, c);
            print(matrix);
        }
        if (t == 1) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<Integer> matrix = new Matrix<Integer>(r, c);
            for (int i = 0; i < r; ++i) {
                for (int k = 0; k < c; ++k) {
                    matrix.setElementAt(i, k, jin.nextInt());
                }
            }
            print(matrix);
        }
        if (t == 2) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<String> matrix = new Matrix<String>(r, c);
            for (int i = 0; i < r; ++i) {
                for (int k = 0; k < c; ++k) {
                    matrix.setElementAt(i, k, jin.next());
                }
            }
            print(matrix);
        }
        if (t == 3) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<String> matrix = new Matrix<String>(r, c);
            for (int i = 0; i < r; ++i) {
                for (int k = 0; k < c; ++k) {
                    matrix.setElementAt(i, k, jin.next());
                }
            }
            print(matrix);
            matrix.deleteRow(jin.nextInt());
            matrix.deleteRow(jin.nextInt());
            print(matrix);
            int ir = jin.nextInt();
            matrix.insertRow(ir);
            for (int k = 0; k < c; ++k) {
                matrix.setElementAt(ir, k, jin.next());
            }
            ir = jin.nextInt();
            matrix.insertRow(ir);
            for (int k = 0; k < c; ++k) {
                matrix.setElementAt(ir, k, jin.next());
            }
            print(matrix);
            matrix.deleteColumn(jin.nextInt());
            matrix.deleteColumn(jin.nextInt());
            print(matrix);
            int ic = jin.nextInt();
            matrix.insertColumn(ir);
            for (int i = 0; i < r; ++i) {
                matrix.setElementAt(i, ic, jin.next());
            }
            ic = jin.nextInt();
            matrix.insertColumn(ic);
            for (int i = 0; i < r; ++i) {
                matrix.setElementAt(i, ic, jin.next());
            }
            print(matrix);
        }
        if (t == 4) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<Integer> matrix = new Matrix<Integer>(r, c);
            for (int i = 0; i < r; ++i) {
                for (int k = 0; k < c; ++k) {
                    matrix.setElementAt(i, k, jin.nextInt());
                }
            }
            print(matrix);
            int nr = jin.nextInt();
            int nc = jin.nextInt();
            matrix.resize(nr, nc);
            print(matrix);
            matrix.fill(jin.nextInt());
            print(matrix);
        }
    }

    public static void print(Matrix<?> m) {
        int r = m.getNumRows();
        int c = m.getNumColumns();
        System.out.println("  " + r + " x " + c);
        System.out.print("    ");
        for (int k = 0; k < c; ++k) {
            System.out.print(k + "    ");
        }
        System.out.println();
        System.out.print("  ");
        for (int k = 0; k < c; ++k) {
            System.out.print("-----");
        }
        System.out.println();
        for (int i = 0; i < r; ++i) {
            System.out.print(i + "|");
            for (int k = 0; k < c; ++k) {
                if (k > 0) System.out.print(" ");
                System.out.print(m.getElementAt(i, k));
            }
            System.out.println();
        }
        System.out.println();
    }

}