Add Boggle board and cell abstractions

WIP: Building subtrees of boggle board based on dictionary

boggler_utils.py

@@ -1,10 +1,63 @@
-'''Dictionary Utils'''
+'''Boggler Utils'''
+
+from __future__ import annotations
+
+class BoardCell:
+    '''Boggle Board cell'''
+    def __init__(self, row: int, col: int, letter: str, adjacent_indexes: list[list[str]]) -> BoardCell:
+        self.row = row
+        self.col = col
+        self.letter = letter
+        self.adjacent_indexes = adjacent_indexes
+
+    def __str__(self):
+        return f"({self.row}, {self.col}: {self.letter}. Adjacent nodes: {self.adjacent_indexes})"
+
+class BoggleBoard:
+    '''Boggle board structure'''
+    def __init__(self, board: list[list[str]], max_word_len: int = 14) -> BoggleBoard:
+        self.height: int = len(board)
+        self.width: int = len(board[0]) if self.height > 0 else 0
+        self.max_word_len = min(max_word_len, self.width * self.height)   # max word length is determined by size of the board
+        self.board = {}
+        for row in range(0, self.height):
+            for col in range(0, self.width):
+                #self.adjacency_dict[(row, col)] = self.__get_adjacent_indexes(row, col)
+                adjacent_indexes = self.__get_adjacent_indexes(row, col)
+                self.board[(row, col)] = BoardCell(row, col, board[row][col], adjacent_indexes)
+
+    def __get_adjacent_indexes(self, row, col):
+        '''Return adjecency list for board of size `row x col`'''
+        indexes = []
+        if row > 0:
+            indexes.append((row-1, col)) # up
+            if col > 0:
+                indexes.append((row-1, col-1)) # up-left
+            if col < self.width:
+                indexes.append((row-1, col+1)) # up-right
+        if row < self.height:
+            indexes.append((row+1, col)) # down
+            if col > 0:
+                indexes.append((row+1, col-1)) # down-left
+            if col < self.width:
+                indexes.append((row+1, col+1)) # down-right
+        if col > 0:
+            indexes.append((row, col-1)) # left
+        if col < self.width:
+            indexes.append((row, col+1)) # right
+        return indexes
+
+    def get_letter_at(self, row: int, col: int) -> str:
+        '''Return the value at the specified row x column'''
+        return self.board[row][col]
+
 class WordNode:
     '''A node that indicates a single letter in a word. Used to populate a WordTree'''
-    def __init__(self, char: str, is_word: bool, children: dict['WordNode'] = None) -> 'WordNode':
+    def __init__(self, char: str, is_word: bool, parent: WordNode = None, children: dict[WordNode] = None) -> WordNode:
         self.char = char
         self.is_word = is_word
         self.children = children if children is not None else {}
+        self.parent = parent
 
     def add_child_node(self, node):
         '''Add child node to `children` dictionary, indexed by the nodes' `char`'''
@@ -17,38 +70,51 @@ class WordNode:
         return self.__str__()
 
 class WordTree:
-    '''A tree populated by WordNode(s) to complete words from a given wordlist'''
-    def __init__(self, wordlist: list[str], alphabet: str, max_word_len: int = 16) -> WordNode:
-
-        self.wordlist = wordlist
+    '''A tree populated by WordNode(s) to complete words from a given root letter and wordlist'''
+    def __init__(self, alphabet: str, root: str, words: list[str] = None, max_word_len = 16) -> WordTree:
+        self.alphabet = alphabet
+        self.wordlist = words
+        self.root = root
+        self.active_node: WordNode = None
         self.max_word_len = max_word_len
-        # Generate root nodes for each letter of the alphabet
         self.tree = {}
-        for char in alphabet:
-            self.tree[char] = WordNode(char, False)
+
+        # Generate root node
+        self.tree[root] = WordNode(root, False)
 
         # Populate tree from wordlist
-        for word in wordlist:
+        for word in words:
             self.__insert_word(word)
 
     def __str__(self):
         return ", ".join(self.wordlist)
 
-    def __insert_word(self, word):
+    def __insert_letter(self, letter: str, parent: WordNode):
+        '''Create WordNode for `letter` and into WordTree under `parent`'''
+        parent.children[letter] = WordNode(letter, False, parent)
+
+    def __insert_word(self, word: str) -> bool:
+        '''Returns True if word was inserted into the tree, otherwise False'''
+        if word is None or word[0] != self.root:
+            return False
         curr_node = self.tree[word[0]]
         # print(word[0])
         for letter in word[1:self.max_word_len]:
             # Insert new WordNode for each letter that doesen't already exist in the tree
             if letter not in curr_node.children:
-                curr_node.children[letter] = WordNode(letter, False)
+                self.__insert_letter(letter, curr_node)
                 # print(letter)
             curr_node = curr_node.children[letter]
         # Mark the last node of the word
         curr_node.is_word = len(word) <= self.max_word_len
         print(f"Added: {word[:self.max_word_len]}")
+        return True
 
-    def search(self, word) -> bool:
+    def search(self, word: str) -> bool:
         '''Return True if a given word is in the tree otherwise return False'''
+        if len(word) == 0 or word is None:
+            return False
+
         curr_node = self.tree[word[0]]
         for char in word[1:]:
             if char not in curr_node.children:
@@ -58,17 +124,65 @@ class WordTree:
 
         return curr_node.is_word
 
+    def generate_board_sub_tree(self, boggle_board: BoggleBoard, start_cell: BoardCell) -> WordTree:
+        '''Return subtree of board given a particular root (first letter)'''
+
+        if start_cell.letter != self.root:
+            print("ERROR: the start_cell and WordTree root must match!")
+            return None
+
+        sub_tree = WordTree(self.alphabet, self.root)
+        root = self.root
+        used_nodes = {}
+
+        sub_tree.active_node = start_cell
+        dict_ptr = self.tree[root]
+        # Build WordTree to max depth
+        for _ in range(0, min(boggle_board.max_word_len, self.max_word_len)):
+            adjacent_letters = [boggle_board.board[pos] for pos in sub_tree.active_node.adjacent_indexes]
+            for pos in sub_tree.active_node.adjacent_indexes:
+                letter = boggle_board.board[pos]
+                if pos not in used_nodes and letter in dict_ptr.children:
+                    sub_tree.active_node.children[letter] = dict_ptr.children[letter]
+                    # TODO: find way to track used_nodes to avoid loops
+                    # either check the word path by recursing up via the parents
+                    # or pass it along, probably rework WordNode or BoardCell or make
+                    # an intermediate object
+                    # used_nodes
+
+        return sub_tree
+
 
 if __name__ == "__main__":
-    tree = WordTree(['anger',
+    sample_dict = [
+        'aero',
+        'anger',
+        'ant',
         'ape',
+        'argue',
+        'ash',
+        'assuage',
+        'aunt',
+        'auspice',
         'bigger',
         'bit',
         'bite',
         'biter',
         'cart',
         'cast',
-        ], "abcdefghijklmnopqrstuvwxyz")
-    print(tree)
-    print(tree.search('cast'))
-    print(tree.search('hype'))
+    ]
+
+    tree = WordTree("abcdefghijklmnopqrstuvwxyz", "a", sample_dict)
+    print(tree.search('anger'))
+    print(tree.search('argues'))
+
+    board = [
+        "aucd",
+        "eegh",
+        "hios",
+        "trea"
+    ]
+
+    boggle_board = BoggleBoard(board)
+    sub_tree = tree.generate_board_sub_tree(boggle_board, boggle_board.board[(3, 3)])
+    print(sub_tree.search("anger"))