WIGGLE SORT

[Fatema110]

This program accepts an array of unsorted numbers and
sorts the array such that arr[0]<arr[1]>arr[2]<arr[3]...

arr is sorted and stored in second array res
res is partitioned into two such that left sub-array 
contains elements less than the elements in right sub-array
Elements in the left sub-array  are added to the even indices of arr
Elements in the right sub-array are added to the odd indices of arr

1. Sample input:1 3 2 2 3 1
   Sample output: [2,3,1,3,1,2]

2. Sample input:1 4 6 2 3 7 9 2 1 0
   Sample Output: [2, 9, 2, 7, 1, 6, 1, 4, 0, 3]

Time Complexity: O(N log N) (Sorting takes O(N logN) and traversal takes O(N))
Space Complexity: O(N) (New array to store the wiggle sorted elements)