/**
 * Created by Rairun on 28.11.2016.
 */
public abstract class QuadMatrix {

    public abstract QuadMatrix createMatrix(int i);

    public abstract double getEl(int m, int n);

    public abstract void setEl(int m, int n, double element);

    public abstract int getSize();

    //Транспонирование матрицы
    public QuadMatrix transpMatrix(QuadMatrix q) {
        QuadMatrix q1 = createMatrix(q.getSize());
        for (int i = 0; i < q.getSize(); i++) {
            for (int j = 0; j < q.getSize(); j++) {
                q1.setEl(j, i, q.getEl(i, j));
            }
        }
        return q1;
    }

    //Нахождение союзной матрицы
    public QuadMatrix sMatrix(QuadMatrix q) {
        double det = 0;
        QuadMatrix sq = createMatrix(q.getSize());
        for (int i = 0; i < q.getSize(); i++) {
            for (int j = 0; j < q.getSize(); j++) {
                if ((i + j) % 2 == 0) {
                    det += determinant(delRC(q, i, j));
                } else {
                    det -= determinant(delRC(q, i, j));
                }
            }
        }
        return sq;
    }


    //Нахождение обратной матрицы
    public QuadMatrix reverseMatrix(QuadMatrix q) {
        if (determinant(q) == 0) {
            return null;
        } else {
            QuadMatrix rMatrix = createMatrix(q.getSize());
            QuadMatrix sm = sMatrix(transpMatrix(q));
            for (int i = 0; i < q.getSize(); i++) {
                for (int j = 0; j < q.getSize(); j++) {
                    rMatrix.setEl(i, j, (1 / determinant(q) * sm.getEl(i, j)));
                }
            }
            return rMatrix;
        }
    }

    //Вычисление детерминанта
    public double determinant(QuadMatrix q) {
        double det = 0;
        if (q.getSize() == 1) {
            return q.getEl(0, 0);
        } else {
            for (int i = 0; i < q.getSize(); i++) {
                if (i % 2 == 0) {
                    det += q.getEl(0, i) * determinant(delRC(q, 0, i));
                } else {
                    det -= q.getEl(0, i) * determinant(delRC(q, 0, i));
                }
            }
        }
        return det;
    }

    //Удаление определёной строки и столбца
    public QuadMatrix delRC(QuadMatrix q, int row, int column) {
        if (q.getSize() == 1) {
            return q;
        } else {
            QuadMatrix q1 = createMatrix(q.getSize() - 1);
            for (int i = 0, ki = 0; i < q1.getSize(); i++, ki++) {
                if (i == row) {
                    for (int j = 0, kj = 0; j < q1.getSize(); j++, kj++) {
                        if (j == column) {
                            kj++;
                            q1.setEl(i, j, q.getEl(ki + 1, kj));
                        } else {
                            q1.setEl(i, j, q.getEl(ki + 1, kj));
                        }
                    }
                    ki++;
                } else {
                    for (int j = 0, kj = 0; j < q1.getSize(); j++, kj++) {
                        if (j == column) {
                            kj++;
                            q1.setEl(i, j, q.getEl(ki, kj));
                        } else {
                            q1.setEl(i, j, q.getEl(ki, kj));
                        }
                    }
                }
            }
            return q1;
        }
    }

    //Перемножение матриц
    public void multMatrix(QuadMatrix q1, QuadMatrix q2) {
        QuadMatrix qm = createMatrix(getSize());
        double sum = 0;
        for (int i = 0; i < getSize(); i++) {
            for (int j = 0; j < getSize(); j++) {
                for (int k = 0; k < getSize(); k++) {
                    sum += q1.getEl(i, k) * q2.getEl(k, j);
                }
                qm.setEl(i, j, sum);
            }
        }
    }
}