Leetcode - Wiggle Sort

Screenshot from 2016-02-22 23:26:29.png

My code:

public class Solution {
    public void wiggleSort(int[] nums) {
        if (nums == null || nums.length == 0)
            return;
        Arrays.sort(nums);
        for (int i = 2; i < nums.length; i += 2) {
            int temp = nums[i];
            nums[i] = nums[i - 1];
            nums[i - 1] = temp;
        }
    }
}

没做出来。。。
今天状态真的很差。不做了。

Anyway, Good luck, Richardo!

My code:

public class Solution {
    public void wiggleSort(int[] nums) {
        if (nums == null || nums.length <= 1) {
            return;
        }
        
        for (int i = 0; i < nums.length - 1; i += 2) {
            if (nums[i] > nums[i + 1]){
                swap(nums, i, i + 1);
            }
        }
        
        for (int i = 1; i < nums.length - 1; i += 2) {
            if (nums[i] < nums[i + 1]) {
                swap(nums, i, i + 1);
            }
        } 
    }
    
    private void swap(int[] nums, int left, int right) {
        int temp = nums[right];
        nums[right] = nums[left];
        nums[left] = temp;
    }
}

之前的做法比较慢，O(n log n)

然后看了答案，
参考：
https://discuss.leetcode.com/topic/40813/1ms-java-solution-with-clear-example

发现有O(n)的做法。也是神奇。

Anyway, Good luck, Richardo! -- 09/04/2016