We are given a nxn partially solved square board and have to solve it according to the following rules
- We need to fill the empty cells in the board with numbers from 1-n
- Numbers from 1-n already on the board cannot be replaced
- Each number from 1-n must appear exactly once in each column of the solved board
- Each number from 1-n must appear exactly once in each row of the solved board
- All n, sqrt(n)xsqrt(n) non-overlapping subgrids must be symmetric
- n is a perfect square and sqrt() used above refers to the square root function