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.
This is same as Reverse Words in a String. (https://leetcode.com/problems/reverse-words-in-a-string/)
1 public class Solution { 2 public void rotate(int[] nums, int k) { 3 if(nums == null || nums.length == 0) return; 4 int len = nums.length; 5 k %= len; 6 reverse(nums, 0, len - 1); 7 reverse(nums, 0, k - 1); 8 reverse(nums, k, len - 1); 9 } 10 11 public void reverse(int[] arr, int start, int end){ 12 while(start < end){ 13 int tmp = arr[start]; 14 arr[start] = arr[end]; 15 arr[end] = tmp; 16 start ++; 17 end --; 18 } 19 } 20 }