Create rotation.py

prabhupant · web-flow · commit 9ae8a5eb7f1a · 2019-08-31T19:36:05.000+05:30
diff --git a/data_structures/array/rotation.py b/data_structures/array/rotation.py
@@ -0,0 +1,24 @@
+def gcd(a, b):
+    if b == 0:
+        return a
+    return gcd(b, a%b)
+
+
+def rotate(arr, d):
+    n = len(arr)
+    g = gcd(n, d)
+
+    for i in range(g):
+        temp = arr[i]
+        j = i
+
+        while 1:
+            k = j + d
+            if k >= n:
+                k = k -n
+            if k == i:
+                break
+            arr[j] = arr[k]
+            j = k
+        
+        arr[j] = temp
