April 2012 Contest Problem Editorials

Problem Tester for the contest was Hiroto Sekido.

Find a special connected block (written by shangjingbo). The Editorials can be found here.

Double Strings (written by Sergey Kulik). The Editorials can be found here.

Greatest Dumpling Fight (written by ishani parekh). The Editorials can be found here.

Lucky Array (written by Vitaliy). The Editorials can be found here.

Stacking Pancakes (written by Kaushik Iska). The Editorials can be found here.

Parallel Computing (written by Tomaz Hocevar). The Editorials can be found here.

PDS Number (written by Anh Duong Quang). The Editorials can be found here.

Fit to Play (written by Vamsi Kavala). The Editorials can be found here.

Similar Graphs (written by David Stolp). The Editorials can be found here

Substrings on a Tree (written by Sergey Kulik). The Editorials can be found here.

use memoization. save results

2★gargnitin123 @ 11 Apr 2012 06:58 PM

use memoization. save results 1000th number then keep returning answeres

@rajneesh2k10 yes you are

isha_adm @ 13 Apr 2012 10:31 PM

@rajneesh2k10 yes you are correct in saying that. There is no need for the extra 1ll in the product.

Take the case x=10^18, y=999; Their lcm overflows and is positive when stored in signed long long. Product of 10^18 and 10^18 is negative because of many overflow cycles. Thus overflow depends on the input too and not just the limits of the input variables.

@ashmish2: no it is not, for

4★sourabh912 @ 15 Apr 2012 08:15 PM

@ashmish2: no it is not, for example for n=4 there are 15 possible combinations instead of 14 (1,1,1,1),(1,1,1,2),(1,1,2,1),(1,1,2,2),(1,1,2,3),(1,2,1,1),(1,2,1,2),(1,2,2,1),(1,2,2,2),1,2,2,3),(1,2,3,1),(1,2,3,2),(1,2,3,3),(1,2,3,4) and (1,2,1,3)

check out this link:

3★kq_viet @ 18 Apr 2012 12:17 PM

check out this link: http://www.codechef.com/node/1062815/revisions/1064751/view I dont know why @@.