Re: ISI INTERVIEW PREP

Posted by deepak on Jul 03, 2012; 8:21am
URL: http://discussion-forum.276.s1.nabble.com/ISI-INTERVIEW-PREP-tp7578819p7578988.html

@Rain Man You can imagine the problem as placing n circles inside a square with a side of 4 such that their centres are atleast root(2) distance apart. The 'outermost' circles will be the ones having their centres coinciding with the vertices of the square. Since the centres of the circles are root(2) apart, the radius of each circle I take as 1/(root(2). So, to make sure my 'binding' square contains all circles, including the outer circles, I must extend the given square upwards, downwards, left and right by the length of the radius. ie, effectively, I'm increasing the side by root(2). And then I compute the ratio of areas to get the number of such circles.