Code review fixes for 5 oldest code files

data_structures/disjoint_set/alternate_disjoint_set.py

@@ -5,13 +5,12 @@
 
 
 class DisjointSet:
-    def __init__(self, set_counts: list) -> None:
+    def __init__(self, set_counts: list[int]) -> None:
         """
         Initialize with a list of the number of items in each set
         and with rank = 1 for each set
         """
         self.set_counts = set_counts
-        self.max_set = max(set_counts)
         num_sets = len(set_counts)
         self.ranks = [1] * num_sets
         self.parents = list(range(num_sets))
@@ -46,9 +45,8 @@
             self.set_counts[src_parent] += self.set_counts[dst_parent]
             self.set_counts[dst_parent] = 0
             self.parents[dst_parent] = src_parent
             joined_set_size = self.set_counts[src_parent]
 
-        self.max_set = max(self.max_set, joined_set_size)
         return True
 
     def get_parent(self, disj_set: int) -> int:

searches/double_linear_search.py

@@ -18,7 +18,11 @@ def double_linear_search(array: list[int], search_item: int) -> int:
     -1
     >>> double_linear_search([1, 5, 5, 10], 10)
     3
+    >>> double_linear_search([], 1)
+    -1
     """
+    if not array:
+        return -1
     # define the start and end index of the given array
     start_ind, end_ind = 0, len(array) - 1
     while start_ind <= end_ind:

searches/double_linear_search_recursion.py

@@ -1,10 +1,10 @@
-def search(list_data: list, key: int, left: int = 0, right: int = 0) -> int:
+def search(list_data: list, key: int, left: int = 0, right: int | None = None) -> int:
     """
     Iterate through the array to find the index of key using recursion.
     :param list_data: the list to be searched
     :param key: the key to be searched
     :param left: the index of first element
-    :param right: the index of last element
+    :param right: the index of last element (defaults to len(list_data) - 1)
     :return: the index of key value if found, -1 otherwise.
 
     >>> search(list(range(0, 11)), 5)
@@ -18,7 +18,8 @@ def search(list_data: list, key: int, left: int = 0, right: int = 0) -> int:
     >>> search([], 1)
     -1
     """
-    right = right or len(list_data) - 1
+    if right is None:
+        right = len(list_data) - 1
     if left > right:
         return -1
     elif list_data[left] == key:

searches/sentinel_linear_search.py

@@ -11,7 +11,7 @@
 """
 
 
-def sentinel_linear_search(sequence, target):
+def sentinel_linear_search(sequence: list, target) -> int | None:
     """Pure implementation of sentinel linear search algorithm in Python
 
     :param sequence: some sequence with comparable items
@@ -31,6 +31,8 @@ def sentinel_linear_search(sequence, target):
     >>> sentinel_linear_search([0, 5, 7, 10, 15], 6)
 
     """
+    # Create a copy to avoid mutating the input sequence
+    sequence = sequence.copy()
     sequence.append(target)
 
     index = 0

strings/remove_duplicate.py

@@ -1,6 +1,9 @@
 def remove_duplicates(sentence: str) -> str:
     """
-    Remove duplicates from sentence
+    Remove duplicate words from sentence and return sorted unique words.
+
+    Note: The output words are sorted alphabetically, not in original order.
+
     >>> remove_duplicates("Python is great and Java is also great")
     'Java Python also and great is'
     >>> remove_duplicates("Python   is      great and Java is also great")