Rotate Array

lc189. Rotate Array.py

@@ -0,0 +1,25 @@
+class Solution:
+
+    def rotate(self, nums, k):
+        """
+        :type nums: List[int]
+        :type k: int
+        :rtype: void Do not return anything, modify nums in-place instead.
+        """
+        def reserve(start, end):
+            for i in range((end - start) // 2):
+                nums[i + start], nums[end - i -
+                                      1] = nums[end - i - 1], nums[i + start]
+
+        length = len(nums)
+        k %= length
+        reserve(length - k, length)
+        reserve(0, length - k)
+        reserve(0, length)
+
+
+nums = [1,2,3,4,5,6,7]
+k = 3
+s = Solution()
+s.rotate(nums, k)
+print(nums)