How to find ∑1
Given two numbers k and n, we have to find ∑1<=i<=n(k mod i), Constraints n>=1 n < k<=10^9 time limit- 1s obvious approach is r = 0; for i from 1 to n do r += (k mod i); return r But it...
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I see some questions in the questions list as closed. If I navigate to a closed question, I don’t see a textbox for answering that question. Also what if I want to reopen the question?
View ArticleWhat is wrong with my code for calculating factorials?
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hey! This is the code for the trianglesum problem. I'm getting an nzec error. I though it is due to some extra spaces problem. But even after using split() it doesn't work. I've checked the forum but...
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View ArticleTime limit is exceeded
Hi,I have written the following code in PHP for problem http://www.codechef.com/problems/A4/while(FALSE !== ($t = fgets(STDIN))) { $n = array(); $k = array(); for($i = 0; $i < $t; $i++) { list($n[],...
View ArticleFind Median in an Unsorted Array Without Sorting it
Given an unsorted Array A[1,2,3,.....N], Find the Medians in this array without sorting it in an efficient Way?
View ArticleACM ICPC 2013 World Final Live
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The Getting Started page should be a page where someone who wants to start programming should be able to find good resources on the web to do so. However, the present page is not adequate. Also it is...
View ArticleWA in ALETHIO (june cookoff)
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View ArticleINVITES - Editorial
Problem Link:PracticeContestDifficulty:MediumPre-requisites:Dynamic Programming, TreeProblem:Given N families, each of whom declares exactly one enemy among the remaining families, find how many ways...
View Articlestone game - wrong Answer
Can someone please tell me where i went wrong? It gives the required output as the test case but it gave me a wrong answer when submitted. Here is the link to my code : http://ideone.com/9Slw9d
View ArticleProblems from ACM ICPC 2013
I would like to ask you if you will post the problem from ACM ICPC 2013 on codechef? (post = put them on practice session).
View ArticleSmall improvements for code chef
I was thinking of what improvements can be done to code chef without some big effort like a new feature but just some small tweaking . I came up with the following list : 1. Include global time...
View Articlewhats wrong..
to calculate:last digit of a^c (a can be upto 1000 digits and c upto 18 digits) plss.. point out the fallacy in the code....#include<iostream.h> #include<math.h> #include<string.h>...
View ArticleDivision of problems by difficulty level
When the editorials are published there are 5 kind of divisions for difficulty level : 1. Cakewalk 2. Simple 3. Easy 4. Medium 5. Hard However , when the problems move to practice section the first...
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