Wave array

Given a sorted array arr[] of distinct integers. Modify the array to look like a wave. In other words, arrange the elements into a sequence such that a1 >= a2 <= a3 >= a4 <= a5.....
Note: The converted array must be the lexicographically smallest wave array.



Example 1:

Input:
N = 5
arr[] = {1,2,3,4,5}
Output: 2 1 4 3 5
Explanation: Array elements after 
sorting it in wave form are 
2 1 4 3 5.
 

Example 2:

Input:
N = 6
arr[] = {2,4,7,8,9,10}
Output: 4 2 8 7 10 9
Explanation: Array elements after 
sorting it in wave form are 
4 2 8 7 10 9.

Your Task:
You do not need to read input or print anything. The task is to complete the function convertToWave() which takes the array and n as input parameters and converts the given array to wave array. The modification must be done in-place without using any extra space. The function does not return anything to the calling function. 


Expected Time Complexity: O(N)
Expected Auxiliary Space: O(1)


Constraints:
1 ≤ N ≤ 106
0 ≤ arr[i] ≤107


class Solution{
public:
    void convertToWave(vector<int>& arr, int n){
        for(int i=0;i<n-1;i=i+2)
        {
            swap(arr[i],arr[i+1]);
        }
    }
};