Project Euler Forum

Wow, only 25 solvers so far. Looks like the toughest problem of this season.

I want to make sure I understand the following correctly

"The wall must be a closed series of straight lines, each line running from post to post."

If I have a slanting line from point a to b, does it have to be like a staircase so that it touches the nearest posts? Either way, I am no where close to solve this, but want to make sure I spend time on the right interpretation.

I thought as long it is a wall between two posts, it would meet the criteria. If not, you could not get past the 125 limit i guess.

Anyone trying to solve it with an integral?

Any straight segment is fine as long as its endpoints are posts.

Hmm i was thinking maybe taking the area as a circle which extends outside the square might do the job. Although i'm still a noob at this . But i am getting a nice value of the ratio around ~131.7, but that's on taking a circular boundary... i've yet to make a straight-lined approximation.

This forum is not for discussing solving strategies. Please refrain from posting anything that might spoil the solving fun for others.

In my opinion, part of the description of question is a little vague. For example,

"251001 posts have been placed in a rectangular grid with 1 meter spacing. The wall must be a closed series of straight lines, each line running from post to post."

Does this mean that we divide the square in a grid of 1x1 boxes? Probably not, because if every post had size 1 then we would need more than 251001 posts to fill the square. I still don't get it. Also, "Each line that runs from post to post" refers to a line that can run only through the ending points of each post or even through the middle of it.

I would appreciate any clarification on these issues. Also, congrats to those who have already solved it.

You can look up what is meant by a post using this link:
http://dictionary.reference.com/browse/post?r=75
You should have the first meaning:

"a strong piece of timber, metal, or the like, set upright as a support, a point of attachment, a place for displaying notices, etc.
"

Thank you for letting me know that there are dictionaries, but I just asked how these posts are used in the description of the problem since it is a little bit unclear. Anyway, thnx for your time, I think I have found the solution.

Well, I thought that if the meaning of the word post was clear there wasn't any ambiguity anymore.
But one never knows.

I understand, I just got confused for a minute but now I get the whole picture. Thnx

Anyone care to look at my working and give me any hints as to how to improve. I'm currently accurate to 2 decimal places (know the numerical answer from ages ago when I first joined and wanted to solve this). I don't have a code as such since I've sort of tried to solve it with pencil/paper and just by looking at a plot of matlab but I can send the coordinates of the posts (not too many of them).