Rotate Array

Rotate an array of

nelements to the right byksteps.For example, with

n= 7 andk= 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.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; } };