```
public class Solution {
public void WiggleSort(int[] nums) {
for(int i=1;i<nums.Length;i+=2)
{
//swap i with num[i-1], then num[i-1] will less than num[i]
if(nums[i]<nums[i-1])
swap(nums,i,i-1);
//num[i-1] is less than num[i] and num[i] is less than num[i+1], so num[i+1] will be larger than num[i-1]
if(i<nums.Length-1&&nums[i]<nums[i+1])
swap(nums,i,i+1);
}
}
private void swap(int[] nums,int i,int j)
{
int temp = nums[i];
nums[i]=nums[j];
nums[j]=temp;
}
}
```