#4 Graphing the board

Sudoku board can now be represented as a graph. Only 9x9 and 4x4 are supported for now.

Pipfile

@@ -4,6 +4,8 @@ verify_ssl = true
 name = "pypi"
 
 [packages]
+matplotlib = "*"
+networkx = "*"
 
 [dev-packages]
 

sudoku/app.py

@@ -1,5 +1,13 @@
 from sudoku.modules.sudoku import Sudoku
+from sudoku.modules.graph import Graph
 
 def run():
     sudoku = Sudoku()
-    sudoku.print_board((sudoku.get_solved_board(9)))
+    board = sudoku.get_solved_board(9)
+
+    sudoku.print_board(board)
+
+    graph = Graph()
+    graph.create_graph(board)
+    graph.show_graph()
+

sudoku/modules/graph.py

@@ -0,0 +1,109 @@
+import networkx as nx
+import matplotlib.pyplot as plt
+
+class Graph:
+
+    def __init__(self):
+        self.board = nx.Graph()
+        self.labels = dict()
+        self.display_labels = dict()
+
+    def create_graph(self, board: list):
+        self._add_nodes(board)
+        self._add_edges(board)
+        self._add_cluster_edges(board)
+
+    def _add_nodes(self, board: list):
+        '''
+        Adds the nodes to the board.
+
+        Parameters:
+        board (list): board.
+        '''
+        label = 0
+        for row in range(len(board)):
+            for col in range(len(board)):
+                label += 1
+                self.labels[(row, col)] = label
+                self.display_labels[label] = board[row][col]
+                self.board.add_node(label)
+
+    def _add_edges(self, board: list):
+        '''
+        Adds the "main" edges to the board.
+
+        Parameters:
+        board (list): board.
+        '''
+        label = 0
+        for row in range(len(board)):
+            for col in range(len(board)):
+                try:
+                    self.board.add_edge(self.labels[row, col],
+                        self.labels[row, col - 1])
+                except (IndexError, KeyError):
+                    pass
+                try:
+                    self.board.add_edge(self.labels[row, col],
+                        self.labels[row + 1, col])
+                except (IndexError, KeyError):
+                    pass
+                try:
+                    self.board.add_edge(self.labels[row, col],
+                        self.labels[row, col + 1])
+                except (IndexError, KeyError):
+                    pass
+                try:
+                    self.board.add_edge(self.labels[row, col],
+                        self.labels[row - 1, col])
+                except (IndexError, KeyError):
+                    pass
+
+    def _add_cluster_edges(self, board: list):
+        '''
+        Adds the edges between "clusters" to the board.
+
+        Parameters:
+        board (list): board.
+        '''
+        size = len(board)
+        divider = 2 if size % 2 == 0 else 3
+        num_sectors = int(size / divider)
+
+        # Find cluster beginnings
+        cluster_beginnings = []
+        for i in range(0, size, divider):
+            for j in range(0, size, divider):
+                cluster_beginnings.append((i, j))
+
+        # Iterate through cluster and add edges.
+        for cluster in cluster_beginnings:
+            current_cluster = []
+            for row in range(cluster[0], cluster[0] + divider):
+                for col in range(cluster[1], cluster[1] + divider):
+                    current_cluster.append((row, col))
+
+            for node in current_cluster:
+                for _ in current_cluster:
+                    self.board.add_edge(
+                        self.labels[node],
+                        self.labels[_]
+                    )
+
+    def show_graph(self):
+        '''
+        Shows the graph.
+
+        Parameters:
+        board (list): board.
+        '''
+        pos = dict((v,k) for k,v in self.labels.items())
+        nx.draw_networkx(
+            self.board,
+            pos=pos,
+            with_labels=True, 
+            node_size=800,
+            labels=self.display_labels
+        )
+        plt.axis('off')
+        plt.show()