leetcode 之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]

Related problem: Reverse Words in a String II

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

好的~，這題在編程珠璣還是編程之美里看過。不記得了。反正題意記着。

訣竅在於兩次翻轉

int len = nums.length;

        if (len == 1 || k == 0 || len == k) {
            return;
        }
        k = k % len;
        for (int i = 0; i < (len - k) / 2; i++) {
            int t = nums[i];
            nums[i] = nums[len - k - i - 1];
            nums[len - k - i - 1] = t;
        }

        for (int i = len - k, j = 1; i < len - k/ 2; i++) {
            int t = nums[i];
            nums[i] = nums[len - j];
            nums[len - j] = t;
            j++;
        }
        for (int i = 0; i < len / 2; i++) {
            int t = nums[i];
            nums[i] = nums[len - i - 1];
            nums[len - i - 1] = t;
        }

它說有三種方法。這是第一種，其它想到再說。
第二種

   public void rotate(int[] nums, int k) {
        int len = nums.length;
        k = k % len;
        if (len == 1 || k == 0 || len == k) {
            return;
        }

        int[] result=new int[len];
        for (int i = 0; i <len; i++) {
            if (i<k) {
                result[k-i-1]=nums[len-i-1];
            }else{
                result[i]=nums[i-k];
            }
        }
        for(int i=0;i<len;i++){
            nums[i]=result[i];
        }

    }