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].

Solution:

  1. public class Solution {
  2.   public void wiggleSort(int[] nums) {
  3.     for (int i = 1; i < nums.length; i++) {
  4.       if (i % 2 != 0 && nums[i] < nums[i - 1]) {
  5.         swap(nums, i, i - 1);
  6.       } else if (i % 2 == 0 && nums[i] > nums[i - 1]) {
  7.         swap(nums, i, i - 1);
  8.       }
  9.     }
  10.   }
  12.   void swap(int[] nums, int i, int j) {
  13.     int tmp = nums[i];
  14.     nums[i] = nums[j];
  15.     nums[j] = tmp;
  16.   }
  17. }