Count all possible paths from top left to bottom right of a mXn matrix | javascript program to count all possible paths from top left to top bottom using combinatorics ; We have to calculate m + n - 2 C n - 1 here which will be ( m + n - 2 ) ! / ( n - 1 ) ! ( m - 1 ) ! ; Driver code
function numberOfPaths ( m , n ) { var path = 1 ; for ( i = n ; i < ( m + n - 1 ) ; i ++ ) { path *= i ; path = parseInt ( path / ( i - n + 1 ) ) ; } return path ; } document . write ( numberOfPaths ( 3 , 3 ) ) ;