Minimum Sum of Product of Two Arrays

Find the minimum sum of Products of two arrays of the same size, given that k modifications are allowed on the first array. In each modification, one array element of the first array can either be increased or decreased by 2.

Input : ar[] = {1, 2, -3}

b[] = {-2, 3, -5}

k = 5

Output : -31

Explanation:

Here n = 3 and k = 5.

So, we modified a[2], which is -3 and

increased it by 10 (as 5 modifications are allowed).

Final sum will be :

(1 * -2) + (2 * 3) + (7 * -5)

-2 + 6 - 35

-31

(which is the minimum sum of the array with given conditions)

Input : a[] = {2, 3, 4, 5, 4}

b[] = {3, 4, 2, 3, 2}

Output : 25

Explanation:

Here, total numbers are 5 and total modifications allowed are 3. So, modify a[1], which is 3 and decreased it by 6 (as 3 modifications are allowed).

Final sum will be :

(2 * 3) + (-3 * 4) + (4 * 2) + (5 * 3) + (4 * 2)

6 – 12 + 8 + 15 + 8

                    25

(which is the minimum sum of the array with given conditions)