title: Counting no of matrices with exactly n/2 zeros and n/2 ones in each row and each column for a given n
body: <p>For a blank n * n matrix, even n, we want to assign zeros and ones to this matrix so
  that each row and each column contains exactly n/2 zeros and n/2 ones for a given n. </p>
  
  <p>Can there be a Dynamic programming method to solve this? I have worked the base case as 0 for a matrix of size 0, then 2 matrices for n = 2. But am not able to get the recursive equation.
  I was asked this in a recent interview with Microsoft.</p>