You are given an $m \times n$ integer matrix grid and an integer k.

In one operation, you can choose any $k \times k$ submatrix of grid and increment every element in that submatrix by $1$.

Return the minimum number of operations required to make all elements in grid equal.

Constraints:

• $1 \leq m ==$ grid.length $\leq 1000$

• $1 \leq n ==$ grid[i].length $\leq 1000$

• $-10^5 \leq$ grid[i][j] $\leq 10^5$

• $1 \leq$ k $\leq \min(m, n)$

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.