Create sliding_window.py

greedy_methods/sliding_window.py

@@ -0,0 +1,45 @@
+def sliding_window(input_string: str) -> int:
+    """
+    This function takes a string and returns the length of the longest substring
+    without repeating characters using the sliding window algorithm.
+
+    Args:
+        input_string: A string input.
+
+    Returns:
+        max_len: Length of the longest substring without repeating characters.
+
+    Examples:
+    >>> sliding_window("abcabcbb")
+    3
+    >>> sliding_window("bbbbb")
+    1
+    >>> sliding_window("pwwkew")
+    3
+    >>> sliding_window("")
+    0
+    >>> sliding_window("abcdefg")
+    7
+    >>> sliding_window("abccba")
+    3
+    """
+    char_index_map: dict[str, int] = {}
+    left = 0
+    max_len = 0
+
+    # Traverse the string with a right pointer
+    for right, char in enumerate(input_string):
+        if char in char_index_map and char_index_map[char] >= left:
+            # Move the left pointer to avoid repeating characters
+            left = char_index_map[char] + 1
+        # Update the latest index of the character
+        char_index_map[char] = right
+        # Calculate the current length of the window
+        max_len = max(max_len, right - left + 1)
+    return max_len
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()