LeetCode 280. Wiggle Sort C#

Given an unsorted array nums, reorder it in-place such that nums[0] <= nums[1] >= nums[2] <= nums[3]....

For example, given nums = [3, 5, 2, 1, 6, 4], one possible answer is [1, 6, 2, 5, 3, 4].

Solution:

Loop through, when odd index num should be greater then the previous num;

                       when even index num should be smaller then the previous num;

So if even index num is greater then the previous num then it must be greater then the previous of previous num too, so only swap once.

 1 public class Solution {
 2     public void WiggleSort(int[] nums) {
 3         int l = nums.Length;
 4         for(int i=1; i<l;i++)
 5         {
 6             if(i%2==1)
 7             {
 8                 if(nums[i]<nums[i-1])
 9                 {
10                     Swap(nums, i);
11                 }
12             }
13             else
14             {
15                 if(nums[i]>nums[i-1])
16                 {
17                     Swap(nums, i);
18                 }
19             }
20         }
21     }
22     public void Swap(int[] nums, int i)
23     {
24         int temp = nums[i-1];
25         nums[i-1]=nums[i];
26         nums[i] = temp;
27     }
28 }