# LeetCode 280. Wiggle Sort

## Description

https://leetcode.com/problems/wiggle-sort/

Given an integer array `nums`, reorder it such that `nums <= nums >= nums <= nums...`.

You may assume the input array always has a valid answer.

Example 1:

```Input: nums = [3,5,2,1,6,4]
Output: [3,5,1,6,2,4]
Explanation: [1,6,2,5,3,4] is also accepted.
```

Example 2:

```Input: nums = [6,6,5,6,3,8]
Output: [6,6,5,6,3,8]
```

Constraints:

• `1 <= nums.length <= 5 * 104`
• `0 <= nums[i] <= 104`
• It is guaranteed that there will be an answer for the given input `nums`.

Follow up: Could you do it without sorting the array?

## Explanation

Sort the list. Then use a temp array, for odds positions, append an element from the beginning of the list. For even positions, append an element from the end of the list.

## Python Solution

``````class Solution:
def wiggleSort(self, nums: List[int]) -> None:
"""
Do not return anything, modify nums in-place instead.
"""

temps = list(sorted(nums))

results = []
for i in range(len(temps)):
if i % 2 == 0:
results.append(temps.pop(0))
else:
results.append(temps.pop())

i += 1

for i, num in enumerate(results):
nums[i] = results[i]``````
• Time Complexity: O(NlogN).
• Space Complexity: O(N).