Hi, everyone!

Recently I was solving problem Plot Purchase from OI 15 and Parcels from OI 9. Then, Errichto shared with me a great article with a similar problem here.

Unfortunately, I am no pole, and even with Google Translate I was not able to understood the idea of the solution mentioned in the blog. Here is the problem mentioned in the blog: Given a N by N square grid of 0s and 1s, compute an array A[N][N], where A[x][y] denotes the number of rectangles of all 0s with height x and width y. The blog solves the task in O(N²).

I'm wondering if anyone (Polish or not), can understand the solution in this blog (I guess there's pseudocode at the end, but I couldn't understand it either) or invent a solution of your own to solve the task. I've thought about it for a few days, to no success.

Thanks!

-minimario