private void button8_Click(object sender, EventArgs e)
        {
            textBox2.Text = "searching...";
            textBox2.Refresh();
            int n_beams = number_of_beams();
            int n_queen = number_of_queen();

            int[][] initialize_beams = new int[n_beams][];
            for (int i = 0; i < n_beams; i++)
            {
                initialize_beams[i] = helper.generate_random_array(n_queen);
            }

            local_beam_search <int[]> lbs = new local_beam_search <int[]>();
            n_queens_problem          nqp = new n_queens_problem();

            int[] result = lbs.solve(nqp, initialize_beams, n_beams);
            textBox2.Text = print_n_queen_result(result);
        }
        private void button11_Click(object sender, EventArgs e)
        {
            textBox9.Text = "searching...";
            textBox9.Refresh();
            int color_constraint = number_of_colors();
            int n_beams          = number_of_beams();

            bool[,] adj_matrix = get_adjacency_matrix();
            int[][] initialize_beams = new int[n_beams][];
            int     n_of_nodes       = number_of_nodes();

            for (int i = 0; i < n_beams; i++)
            {
                initialize_beams[i] = helper.generate_random_array(n_of_nodes, color_constraint);
            }
            local_beam_search <int[]> lbs = new local_beam_search <int[]>();
            graph_coloring            gc  = new graph_coloring(adj_matrix, color_constraint);

            int[] result = lbs.solve(gc, initialize_beams, n_beams);
            textBox9.Text = print_graph_coloring_result(gc, result);
        }