# Rotate Array

Rotate an array of n elements to the right by k steps.

For example, with n = 7 and k = 3, the array `[1,2,3,4,5,6,7]` is rotated to `[5,6,7,1,2,3,4]`.

Note:
Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.

```class Solution:
# @param nums, a list of integer
# @param k, num of steps
# @return nothing, please modify the nums list in-place.
def rotate(self, nums, k):
for i in range(0, k):
nums[i] = nums[i] + len(nums) - k
for i in range(k, len(nums)):
nums[i] = nums[i] - k
print nums```

```Runtime Error Message:	Line 7: IndexError: list index out of range
Last executed input:	[-1], 2```

index越界，一看就是平时写代码肆意不严格导致的，k比length大就出错了

```class Solution:
# @param nums, a list of integer
# @param k, num of steps
# @return nothing, please modify the nums list in-place.
def rotate(self, nums, k):
length = len(nums)
if k > length:
k = k % length
for i in range(0, k):
nums[i] = nums[i] + length - k
for i in range(k, length):
nums[i] = nums[i] - k
print nums```

`Status: Output Limit Exceeded`

```class Solution:
# @param nums, a list of integer
# @param k, num of steps
# @return nothing, please modify the nums list in-place.
def rotate(self, nums, k):
length = len(nums)
k = k % length
array1 = nums[:(length - k)]
array2 = nums[(length - k):]
nums = array2 + array1
print nums```

```Status: Wrong Answer

Input:	[1,2], 1
Output:	[1,2]
Expected:	[2,1]```