Leetcode 280. Wiggle Sort

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].

观察wiggle sort之后的结果可知：

nums[even] <= nums[even+1] (index从0开始)

nums[odd] >= nums[odd+1]

依次检查每一个元素，如果不符合这个条件就和下一个元素交换一下。

class Solution(object):
    def wiggleSort(self, nums):
        """
        :type nums: List[int]
        :rtype: void Do not return anything, modify nums in-place instead.
        """
        n = len(nums)
        for i in range(n-1):
            if i%2 == 0 and nums[i] > nums[i+1]:
                    nums[i], nums[i+1] = nums[i+1], nums[i]
            elif i%2 == 1 and nums[i] < nums[i+1]:
                    nums[i], nums[i+1] = nums[i+1], nums[i]