Given an array Arr[] of size N and an integer K, you have to choose the first two minimum elements of the array and erase them, then insert the sum of these two elements in the array until all the elements are greater than or equal to K and find the number of such operations required.
Example 1:
Input:
N = 6, K = 6
Arr[] = {1, 10, 12, 9, 2, 3}
Output: 2
Explanation: First we add (1 + 2), now the
new list becomes 3 10 12 9 3, then we add
(3 + 3), now the new list becomes 6 10 12 9,
Now all the elements in the list are greater
than 6. Hence the output is 2 i:e 2 operations
are required to do this.
Example 2:
Input:
N = 4, K = 4
Arr[] = {5, 4, 6, 4}
Output: 0
Explanation: Every element in the given array
is greater than or equal to K.
Your Task:
You don't need to read input or print anything. Your task is to complete the function minOperations() which takes array of integers arr, n and k as parameters and returns an integer denoting the answer. If it is not possible to make elements greater than or equal to K, return -1.
Expected Time Complexity: O(N*logN)
Expected Auxiliary Space: O(N)
Constraints :
1 ≤ N, K ≤ 10^{5}
1 ≤ Arr[i] ≤ 10^{6}

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