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]
题解：
func rotate(nums []int, k int) {k = k % len(nums) reverse(nums)reverse(nums[k:])reverse(nums[:k])
}func reverse(nums []int) {for l,r:=0,len(nums) - 1; l < len(nums) / 2; l, r = l+1, r-1 {nums[l],nums[r] = nums[r],nums[l]}
}
class Solution {public void rotate(int[] nums, int k) {k = k % nums.length;reverse(nums, 0, nums.length - 1);reverse(nums, 0, k - 1);reverse(nums, k, nums.length - 1);}// 反转数组public void reverse(int[] nums, int l, int r) {while (l < r) {int tmp = nums[l];nums[l] = nums[r];nums[r] = tmp;l++;r--;}}
}