public boolean isValid() {
37
        return (this.isRowValid() & this.isComValid() & this.isGridValid());
38
    }
39

40
    /**
41
     * proves if the rows is valide after the rules for sudoku.
42
     *
43
     * @return boolean if the rows is valide
44
     */
45
    public boolean isRowValid() {
46
        for (int col9 = 0; col9 < 9; col9++) {
47
            for (int row9 = 0; row9 < 9; row9++) {
48
                for (int row2 = 0; row2 < 9; row2++) {
49
                    if (getValueAt(row9, col9) != -1) {
50
                        if ((getValueAt(row9, col9) == getValueAt(row2, col9)) && (row9 != row2)) {
51
                            return false;
52
                        }
53
                    }
54
                }
55
            }
56
        }
57
        return true;
58
    }
59

60
    /**
61
     * proves if the colums is valide after the rules for sudoku.
62
     *
63
     * @return boolean if the colums is valide
64
     */
65
    public boolean isComValid() {
66
        for (int row0 = 0; row0 < 9; row0++) {
67
            for (int col0 = 0; col0 < 9; col0++) {
68
                for (int col2 = 0; col2 < 9; col2++) {
69
                    if (getValueAt(row0, col0) != -1) {
70
                        if ((getValueAt(row0, col0) == getValueAt(row0, col2)) && (col0 != col2)) {
71
                            return false;
72
                        }
73
                    }
74
                }
75
            }
76
        }
77
        return true;
78
    }
79

80
    /**
81
     * prooves if one spesific 3 times 3 grid on the board is valid.
82
     *
83
     * @param x for the cordinat of the upper left corner of the grid.
84
     * @param y for the cordinat of the upper left corner of the grid.
85
     * @return boolean if that one grid its called on is valid.
86
     */
87
    /*
88
     * public boolean isOneGridValid(int x, int y) { Set<Integer> set = new
89
     * HashSet<>(); for (int i = 1; i < 10; i++) set.add(i); set.add(-1); for (int
90
     * row = x; row < x + 4; row++) { for (int col = y; col < y + 4; col++) { if
91
     * (!set.contains(getValueAt(row, col))) { return false; }
92
     * set.remove(getValueAt(row, col)); set.add(-1); } } return true; }
93
     */
94
    /**
95
     * look if there are no dobble number in one 3 times 3 grid.
96
     *
97
     * @param x coordiate for upper left corner of grid
98
     * @param y coordiate for upper left corner of grid
99
     * @return if one grid is valid
100
     */
101
    public boolean isOneGridValid(int x, int y) {
102
        for (int col = y; col <= y + 3; col++) {
103
            for (int row = x; row <= x + 3; row++) {
104
                for (int col1 = col; col1 <= y + 2; col1++) {
105
                    for (int row1 = row; row1 <= x + 2; row1++) {
106
                        if (getValueAt(row, col) != -1) {
107
                            if ((getValueAt(row, col) == getValueAt(row1, col1)) && ((col != col1) && (row != row1))) {
108
                                return false;
109
                            }
110
                        }
111
                    }
112
                }
113
            }
114
        }
115
        return true;
116
    }
117

118
    /**
119
     * this mathod proves if the number is the grids are valid.
120
     *
121
     * @return boolean if the whole grid is valid.
122
     */
123
    public boolean isGridValid() {
124
        for (int row6 = 0; row6 < 7; row6 += 3) {
125
            for (int col6 = 0; col6 < 7; col6 += 3) {
126
                if (!this.isOneGridValid(row6, col6))
127
                    // if (!this.isOneGridValid(row6, col6))
128
                    return false;
129
            }
130
        }
131
        return true;
132
    }
133