We are given a square board of size n*n, and (n-1)*(n-1) quadrant sums which represent the intended sum of each of the (n-1)*(n-1) 2x2 qudrants in the row major order.
- The input board is partially filled, with empty cells being denoted by 0s
- Non-Zero values already on the board cannot be removed from the board
- We need to completely fill the board such that each number from 1 to n*n appears exactly once on the board
- We should fill the board such that, each of the (n-1)* (n-1) quadrants on the board, have the expected sum as specified in the input
- A quadrant is a 2x2 subgrid