/*
    Time: O(n)
    Space: O(1)
*/

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