Enhanced Trie with case insensitivity, word '

deletion, and improved readability.

Author: sowndappan5

strings/autocomplete_using_trie.py

@@ -8,24 +8,42 @@ def __init__(self) -> None:
         self._trie: Dict[str, Union[Dict, bool]] = {}
 
     def insert_word(self, word: str) -> None:
-        """Inserts a word into the trie."""
+        """Inserts a word into the trie, case insensitive."""
         node = self._trie
+        word = word.lower()
         for char in word:
             if char not in node:
                 node[char] = {}
             node = node[char]
         node[END] = True
 
-    def find_word(self, prefix: str) -> Union[List[str], Tuple[str]]:
-        """Finds all suffixes in the trie that match the given prefix."""
+    def find_word(self, prefix: str) -> Union[List[str], Tuple[str, ...]]:
+        """Finds all suffixes in the trie that match the given prefix, case insensitive."""
         node = self._trie
+        prefix = prefix.lower()
         for char in prefix:
             if char in node:
                 node = node[char]
             else:
                 return []
         return self._elements(node)
 
+    def delete_word(self, word: str) -> None:
+        """Deletes a word from the trie if it exists, case insensitive."""
+        def _delete(node: Dict[str, Union[Dict, bool]], word: str, depth: int) -> bool:
+            if depth == len(word):
+                if END in node:
+                    del node[END]
+                    return len(node) == 0
+                return False
+            char = word[depth]
+            if char in node and _delete(node[char], word, depth + 1):
+                del node[char]
+                return len(node) == 0
+            return False
+        
+        _delete(self._trie, word.lower(), 0)
+
     def _elements(self, node: Dict[str, Union[Dict, bool]]) -> Tuple[str, ...]:
         """Recursively collects all words from the current node."""
         result = []
@@ -37,20 +55,17 @@ def _elements(self, node: Dict[str, Union[Dict, bool]]) -> Tuple[str, ...]:
                 result.extend(sub_result)
         return tuple(result)
 
-trie = Trie()
-words = ("depart", "detergent", "daring", "dog", "deer", "deal")
-for word in words:
-    trie.insert_word(word)
-
-def autocomplete_using_trie(prefix: str) -> Tuple[str, ...]:
+# Example usage of the enhanced Trie class
+def autocomplete_using_trie(prefix: str, trie: Trie) -> Tuple[str, ...]:
     """
     Autocompletes the given prefix using the trie.
 
     >>> trie = Trie()
+    >>> words = ("depart", "detergent", "daring", "dog", "deer", "deal")
     >>> for word in words:
     ...     trie.insert_word(word)
     ...
-    >>> matches = autocomplete_using_trie("de")
+    >>> matches = autocomplete_using_trie("de", trie)
     >>> "detergent" in matches
     True
     >>> "dog" in matches
@@ -60,7 +75,13 @@ def autocomplete_using_trie(prefix: str) -> Tuple[str, ...]:
     return tuple(prefix + suffix for suffix in suffixes)
 
 def main() -> None:
-    print(autocomplete_using_trie("de"))
+    trie = Trie()
+    words = ("depart", "detergent", "daring", "dog", "deer", "deal")
+    for word in words:
+        trie.insert_word(word)
+    print(autocomplete_using_trie("de", trie))
+    trie.delete_word("detergent")
+    print(autocomplete_using_trie("de", trie))
 
 if __name__ == "__main__":
     import doctest