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].

此题需要把数组序号分成偶数和奇数来区别对待，代码如下：

public class Solution {

    public void wiggleSort(int[] nums) {

        for(int i=0;i<nums.length-1;i++){

            if(i%2==0){

                if(nums[i]>nums[i+1]) swap(nums,i,i+1);

            }else{

                if(nums[i]<nums[i+1]) swap(nums,i,i+1);

            }

        }

    }

    public void swap(int[] nums,int i,int j){

        int temp = nums[i];

        nums[i] = nums[j];

        nums[j] = temp;

    }

}

280. Wiggle Sort