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.

给定一个n个长度的数组，将它向右旋转k个位置。

 

    private void reverse(int nums[],int begin,int end)
    {
        while(begin<end)
        {
            int temp = nums[begin];
            nums[begin] = nums[end];
            nums[end] = temp;
            begin++;end--;
        }
    }
    
    public void rotate(int[] nums, int k) {
        if (k ==0) return;
        if (nums.length < 2) return;
        k %= nums.length;
        reverse(nums,0,nums.length - 1);
        reverse(nums,0,k - 1);
        reverse(nums,k,nums.length - 1);
    }