280 Wiggle Sort

280. Wiggle Sort

1. Question

Given an unsorted arraynums, reorder itin-placesuch thatnums[0] <= nums[1] >= nums[2] <= nums[3]....

For example, givennums = [3, 5, 2, 1, 6, 4], one possible answer is[1, 6, 2, 5, 3, 4].

2. Implementation

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

    public void swap(int[] nums, int i, int j) {
        int temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }
}

3. Time & Space Complexity

时间复杂度O(n), 空间复杂度O(1)