refactor(trie): fix none check

Author: BrianLusina

datastructures/trees/trie/trie.py

@@ -43,7 +43,7 @@ def insert(self, word: str, index: Optional[int] = None) -> None:
 
         for char in word:
             curr = curr.children[char]
-            if index:
+            if index is not None:
                 curr.index = min(curr.index or float("inf"), index)
 
         curr.is_end = True

datastructures/trees/trie/trie_node.py

@@ -59,4 +59,4 @@ def search_prefix(self, prefix: str) -> int:
             # Traverse to the next node
             current = current.children[char]
 
-        return current.index
+        return current.index if current.index is not None else -1