189. 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.

Related problem: Reverse Words in a String II

解答

三次翻转
第一次将整个数组反转，第二次将前k个元素翻转，第三次将剩下的元素翻转。

class Solution {public:    void rotate(vector<int>& nums, int k) {        if(nums.empty())            return;        int n = nums.size();        if(k == n)            return;        if(k>n)            k = k%n;        reverse(nums.begin(),nums.end());        vector<int>::iterator rotatePoint = nums.begin()+k;        reverse(nums.begin(),rotatePoint);        reverse(rotatePoint,nums.end());    }};