LeetCode Wiggle Sort

 1 public class Solution {
 2     public void wiggleSort(int[] nums) {
 3         if(nums == null || nums.length == 0){
 4             return;
 5         }
 6         for(int i = 1; i<nums.length; i++){
 7             if(i%2 == 1){
 8                 if(nums[i] < nums[i-1]){
 9                     swap(nums, i-1, i);
10                 }
11             }else{
12                 if(nums[i] > nums[i-1]){
13                     swap(nums, i-1, i);
14                 }
15             }
16         }
17     }
18     private void swap(int [] nums, int i, int j){
19         int temp = nums[i];
20         nums[i] = nums[j];
21         nums[j] = temp;
22     }
23 }