TheAlgorithms · RaymondDashWu · Oct 19, 2023 · Oct 19, 2023 · Oct 19, 2023 · Oct 20, 2023
diff --git a/searches/interpolation_search.py b/searches/interpolation_search.py
@@ -3,13 +3,39 @@
 """
 
 
-def interpolation_search(sorted_collection, item):
+def interpolation_search(
+    sorted_collection: list[int] | tuple[int], item: int
+) -> int | None:
     """Pure implementation of interpolation search algorithm in Python
     Be careful collection must be ascending sorted, otherwise result will be
     unpredictable
     :param sorted_collection: some ascending sorted collection with comparable items
     :param item: item value to search
     :return: index of found item or None if item is not found
+    >>> interpolation_search([-1, 0, 1], -1)
+    0
+    >>> interpolation_search([-1, 0, 1], 2) == None
+    True
+    >>> interpolation_search([], -1) == None
+    True
+    >>> interpolation_search((-1, 0, 1), 0)
+    1
+    >>> interpolation_search(range(100), 99)
+    99
+    >>> interpolation_search({-1, 0, 1}, -1)
+    Traceback (most recent call last):
+        ...
+    TypeError: 'set' object is not subscriptable
+    >>> interpolation_search([-1.0, 0, 1], -1.0)
+    Traceback (most recent call last):
+        ...
+    TypeError: list indices must be integers or slices, not float
+    >>> interpolation_search(["A", "B", "C"], "C")
+    Traceback (most recent call last):
+        ...
+    TypeError: unsupported operand type(s) for -: 'str' and 'str'
+    >>> interpolation_search({1:4, 2:9, 0:42}, 1) == None
+    True
     """
     left = 0
     right = len(sorted_collection) - 1
@@ -48,14 +74,42 @@ def interpolation_search(sorted_collection, item):
     return None
 
 
-def interpolation_search_by_recursion(sorted_collection, item, left, right):
+def interpolation_search_by_recursion(
+    sorted_collection: list[int] | tuple[int], item: int, left: int, right: int
+) -> int | None:
     """Pure implementation of interpolation search algorithm in Python by recursion
     Be careful collection must be ascending sorted, otherwise result will be
     unpredictable
     First recursion should be started with left=0 and right=(len(sorted_collection)-1)
     :param sorted_collection: some ascending sorted collection with comparable items
     :param item: item value to search
     :return: index of found item or None if item is not found
+    >>> interpolation_search_by_recursion([-1, 0, 1], -1, 0, 2)
+    0
+    >>> interpolation_search_by_recursion([-1, 0, 1], 2, 0, 2) == None
+    True
+    >>> interpolation_search_by_recursion([], -1, 0, 0) == None
+    Traceback (most recent call last):
+        ...
+    IndexError: list index out of range
+    >>> interpolation_search_by_recursion((-1, 0, 1), 0, 0, 2)
+    1
+    >>> interpolation_search_by_recursion(range(100), 99, 0, 99)
+    99
+    >>> interpolation_search_by_recursion({-1, 0, 1}, -1, 0, 2)
+    Traceback (most recent call last):
+        ...
+    TypeError: 'set' object is not subscriptable
+    >>> interpolation_search_by_recursion([-1.0, 0, 1], -1.0, 0, 2)
+    Traceback (most recent call last):
+        ...
+    TypeError: list indices must be integers or slices, not float
+    >>> interpolation_search_by_recursion(["A", "B", "C"], "C", 0, 2)
+    Traceback (most recent call last):
+        ...
+    TypeError: unsupported operand type(s) for -: 'str' and 'str'
+    >>> interpolation_search_by_recursion({1:4, 2:9, 0:42}, 1, 0, 2) == None
+    True
     """
 
     # avoid divided by 0 during interpolation