Aisuko · July 18, 2023 04:56 · Jul 18, 2023
diff --git a/sliding_window.py b/sliding_window.py
@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+
+def max_sum(arr, k):
+    """
+    It is used to find the maxumum or minimum sum, product, etc.
+    Time complexity: O(n)
+    """
+    n = len(arr)
+    if n < k:
+        print("Invalid operation")
+        return -1
+    window_sum = sum(arr[:k])
+    max_sum = window_sum
+    for i in range(n-k):
+        window_sum = window_sum - arr[i] + arr[i+k]
+        max_sum = max(window_sum, max_sum)
+    return max_sum
+
+
+if __name__ == "__main__":
+    assert max_sum([100,200,300,400], 2) == 700
+    assert max_sum([2,3], 4) == -1