project euler problem 255

Rounded Square Roots

The first time I saw this problem, I feels that this is a Monte Carlo problem. But I did not try MC, since that is a no-brainer. No way! There are so many 
14 digits number and the problem asked for 10 decimal places. 

I thought about this problem for months, I always got bored by it in a few minutes.

Then finally one day I see something in 5 digits case.  The problem is solved. I love it so much now!  Evil!

I feel problems between 250 and 260 are very difficult to solve.  

252 convex hole
253 caterpillar
254 sum of digit factorial
255 rounded square root
256 tatami
257 angular bisetctor
258 lagged fibonacci sequence
261 pivotal square sum

Some of the problems are still unsolved, some of them took me very long time to figure
out how to solve. 

I am addicted to PE.....