added rotate_array.py

data_structures/arrays/rotate_array.py

@@ -0,0 +1,37 @@
+from typing import List
+
+
+def rotate_array(arr: List[int], k: int) -> List[int]:
+    n = len(arr)
+    if n == 0:
+        return arr
+
+    k = k % n
+
+    if k < 0:
+        k += n
+
+    def reverse(start: int, end: int) -> None:
+        while start < end:
+            arr[start], arr[end] = arr[end], arr[start]
+            start += 1
+            end -= 1
+
+    reverse(0, n - 1)
+    reverse(0, k - 1)
+    reverse(k, n - 1)
+
+    return arr
+
+
+if __name__ == "__main__":
+    examples = [
+        ([1, 2, 3, 4, 5], 2),
+        ([1, 2, 3, 4, 5], -2),
+        ([1, 2, 3, 4, 5], 7),
+        ([], 3),
+    ]
+
+    for arr, k in examples:
+        rotated = rotate_array(arr.copy(), k)
+        print(f"Rotate {arr} by {k}: {rotated}")