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。

 

 1     private void reverse(int nums[],int begin,int end)
 2     {
 3         while(begin<end)
 4         {
 5             int temp = nums[begin];
 6             nums[begin] = nums[end];
 7             nums[end] = temp;
 8             begin++;end--;
 9         }
10     }
11     
12     public void rotate(int[] nums, int k) {
13         if (k ==0) return;
14         if (nums.length < 2) return;
15         k %= nums.length;
16         reverse(nums,0,nums.length - 1);
17         reverse(nums,0,k - 1);
18         reverse(nums,k,nums.length - 1);
19     }

 

posted @ 2017-10-14 21:34  daniel456  阅读(94)  评论(0编辑  收藏  举报