[leetcode 189][轮转数组]
[leetcode 189][轮转数组]
给定一个整数数组 nums，将数组中的元素向右轮转 k 个位置，其中 k 是非负数。
示例 1:
输入: nums = [1,2,3,4,5,6,7], k = 3
输出: [5,6,7,1,2,3,4]
解释:
向右轮转 1 步: [7,1,2,3,4,5,6]
向右轮转 2 步: [6,7,1,2,3,4,5]
向右轮转 3 步: [5,6,7,1,2,3,4]
示例 2:
输入：nums = [-1,-100,3,99], k = 2
输出：[3,99,-1,-100]
解释:
向右轮转 1 步: [99,-1,-100,3]
向右轮转 2 步: [3,99,-1,-100]
class Solution {public static void rotate(int[] nums, int k) {int n = nums.length;if (n <= 1) {return;}int index = k % n;reverse(nums, 0 , n - 1);reverse(nums, 0, index - 1);reverse(nums, index, n - 1);}public static void reverse(int[] nums, int start, int end) {while (end >= start) {int temp = nums[start];nums[start] = nums[end];nums[end] = temp;start++;end--;}}
}