280. Wiggle Sort

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

Example:

Input:
nums = [3,5,2,1,6,4]
Output:
 One possible answer is [3,5,1,6,2,4]

Solution

(1) Java

class Solution {
    public void wiggleSort(int[] nums) {
        for (int i = 1; i < nums.length; i++) {
            if (i%2 == 1 && nums[i] < nums[i-1]) {
                int tmp = nums[i];
                nums[i] = nums[i-1];
                nums[i-1] = tmp;
            } else if (i%2 == 0 && nums[i] > nums[i-1]) {
                int tmp = nums[i];
                nums[i] = nums[i-1];
                nums[i-1] = tmp;
            } 
        }
    }
}

(2) Python

(3) Scala