[Documentation] knuth_morris_pratt (keon#835)

* attach documentation to method; add annotations

* add test case for list of integers

Co-authored-by: Pieter Eendebak <[email protected]>

algorithms/strings/knuth_morris_pratt.py

@@ -1,13 +1,23 @@
-"""
-Given two strings text and pattern,
-return the list of  start indexes in text that matches with the pattern
-using knuth_morris_pratt algorithm.
-If idx is in the list, text[idx : idx + M] matches with pattern.
-Time complexity : O(N+M)
-N and M is the length of text and pattern, respectively.
-"""
+from typing import Sequence, List
 
-def knuth_morris_pratt(text, pattern):
+def knuth_morris_pratt(text : Sequence, pattern : Sequence) -> List[int]:
+    """
+    Given two strings text and pattern, return the list of start indexes in text that matches with the pattern
+    using knuth_morris_pratt algorithm.
+
+    Args:
+        text: Text to search
+        pattern: Pattern to search in the text
+    Returns:
+        List of indices of patterns found
+
+    Example:
+        >>> knuth_morris_pratt('hello there hero!', 'he')
+        [0, 7, 12]
+
+    If idx is in the list, text[idx : idx + M] matches with pattern.
+    Time complexity of the algorithm is O(N+M), with N and M the length of text and pattern, respectively.
+    """
     n = len(text)
     m = len(pattern)
     pi = [0 for i in range(m)]

tests/test_strings.py

@@ -610,6 +610,7 @@ def test_knuth_morris_pratt(self):
         self.assertEqual([0, 1, 2, 3, 4], knuth_morris_pratt("aaaaaaa", "aaa"))
         self.assertEqual([0, 4], knuth_morris_pratt("abcdabc", "abc"))
         self.assertEqual([], knuth_morris_pratt("aabcdaab", "aba"))
+        self.assertEqual([0, 4], knuth_morris_pratt([0,0,1,1,0,0,1,0], [0,0]))
 
 
 class TestPanagram(unittest.TestCase):