text: Count of paths from mid point to end point
code: X = ( ( N - 1 ) - ( N - 1 ) / 2 ) + ( ( M - 1 ) - ( M - 1 ) / 2 ) ; Y = ( ( N - 1 ) - ( N - 1 ) / 2 ) ; midCount *= ncr ( X , Y ) ; answer -= midCount ; } return answer ; }