280 Wiggle Sort

Problem:

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].

Solutions:

public class Solution {
    public void wiggleSort(int[] nums) {
        Arrays.sort(nums);
        for (int i = 2; i< nums.length;) {
            int tmp = nums[i];
            nums[i] = nums[i -1];
            nums[i - 1] = tmp;
            i = i + 2;
        }
    }
}

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