leetcode——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.

class Solution {
public:
    void rotate(vector<int>& nums, int k) {
        
        
        int n = nums.size();
        k = k%n;
        
        reverse(nums,0,n-k-1);
        reverse(nums,n-k,n-1);
        reverse(nums,0,n-1);
        
    }
private:    
    void  reverse(vector<int>& nums, int start, int end) {  
        int i = start;  
        int j = end;  
        int temp = 0;  
        while (i<j) {  
            temp = nums[i];  
            nums[i] = nums[j];  
            nums[j] = temp;  
            ++i;  
            --j;  
        }  
        return;  
    }  

};