  InterviewBit Academy is now Scaler Academy! # Sum of minimum and maximum elements of all subarrays of size k

Given an array A of both positive and negative integers.

Your task is to compute sum of minimum and maximum elements of all sub-array of size B.

Note: Since the answer can be very large, you are required to return the sum module 1000000007.

Input Format

``````The first argument denotes the array A.
The second argument denotes the value B
``````

Output Format

``````Return an integer that denotes the required value.
``````

Constraints

``````1 <= size of array A <= 100000
-1000000000 <= A[i] <= 1000000000
1 <= B <= size of array
``````

** Example**

``````Example Input 1:
A[] = {2, 5, -1, 7, -3, -1, -2}
B = 4

Example Output 1:
18
Explanation :
Subarrays of size 4 are :
{2, 5, -1, 7},   min + max = -1 + 7 = 6
{5, -1, 7, -3},  min + max = -3 + 7 = 4
{-1, 7, -3, -1}, min + max = -3 + 7 = 4
{7, -3, -1, -2}, min + max = -3 + 7 = 4
Sum of all min & max = 6 + 4 + 4 + 4
= 18
``````
NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a doubt? Checkout Sample Codes for more details. Hints
• Hints are not available for this problem