# [leetcode] Rotate Array

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.

[show hint]

Hint:
Could you do it in-place with O(1) extra space?

Related problem: Reverse Words in a String II

Credits:
Special thanks to @Freezen for adding this problem and creating all test cases.

Easy question, but ask the interviewer what we should do if k is bigger than nums.size()

```//What if k is bigger than n?
class Solution {
public:
void rotate(vector<int>& nums, int k) {
//extreme case
if(nums.size() == 0 || k == 0) return ;
k = k % nums.size();//k may be 0
for(int i = 0; i < k; i++){
nums.insert(nums.begin(), nums.back());
nums.pop_back();
}
}
};```

Another approach

```class Solution {
public:
void rotate(vector<int>& nums, int k) {
if(k == 0 || nums.size() == 0)
return;
k %= nums.size();
int len = nums.size();
vector<int> ans;
ans = vector<int>(nums.end() - k, nums.end());
for(size_t i = 0; i < len - k; i++){
ans.push_back(nums[i]);
}
nums = ans;
}
};``` This site uses Akismet to reduce spam. Learn how your comment data is processed.