BdIO-2012 Dhaka

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sm.joty
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BdIO-2012 Dhaka

Unread post by sm.joty » Mon Jan 23, 2012 12:32 am

Hey, friends here is the problem set of BdIO-2012 Dhaka. We should discuss about it. :D
Now everybody, try to solve it.

(N.B: If anyone think that it is not appropriate to post this. Then tell this as post that then the moderator can do something about this. But in my sense there no problem to post this.)
Attachments
BdOI Divisional.pdf
Bangladesh Informatics Olympiad-2012 regional Dhaka.
(80.04 KiB) Downloaded 312 times
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

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amlansaha
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Re: BdIO-2012 Dhaka

Unread post by amlansaha » Wed Feb 01, 2012 6:37 pm

বাহ, ভাল কাজ করেছ জ্যোতি। ধন্যবাদ :) এইটা পাইলা কই?
অম্লান সাহা

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sm.joty
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Re: BdIO-2012 Dhaka

Unread post by sm.joty » Thu Feb 02, 2012 12:19 pm

From Mahmud vaiya. :D
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

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nafistiham
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Re: BdIO-2012 Dhaka

Unread post by nafistiham » Thu Feb 02, 2012 2:11 pm

$3.$ Little K is writing a program to check whether two rectangles (say the are A and
B) intersect each other. Her algorithm is simple. She takes rectangle A and checks
whether each vertex of it lies within rectangle B. Is there any flaw in her
algorithm? Draw counter example if there is any. (7)
Ans :
rectangles.JPG
rectangles.JPG (22.69 KiB) Viewed 2260 times
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
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Re: BdIO-2012 Dhaka

Unread post by nafistiham » Thu Feb 02, 2012 2:45 pm

$5.$ How many ways to arrange 6 cows and 8 donkeys in a line to take photo?
Curiously you can not distinguished a cow from other cows and you can not
distinguished a donkey from other donkeys. (5)
Ans :
\[\frac{14!}{6!8!}\]

$7.$ A number is written with 27 ones. Is it a multiple of 27? Prove your answer and
find the remainder. (10)
Ans :
logically,
it is divisible by $9$ when divided, the number will be divisible by $3$ because, $111111111$ is divisible by $9$ so, the residuw is $0$
analytically,
$X=\underline{1111\cdot\cdot\cdot\cdot\cdot1111}_{27}=111111111\cdot10^{18}+111111111\cdot10^9+111111111$
$\frac{X}{9}=123456791234567912345679$
which is divisible by $3$
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
Using $L^AT_EX$ and following the rules of the forum are very easy but really important, too.Please co-operate.
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*Mahi*
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Re: BdIO-2012 Dhaka

Unread post by *Mahi* » Sat Feb 04, 2012 12:39 pm

Go on @nafistiham :)
Please read Forum Guide and Rules before you post.

Use $L^AT_EX$, It makes our work a lot easier!

Nur Muhammad Shafiullah | Mahi

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nafistiham
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Re: BdIO-2012 Dhaka

Unread post by nafistiham » Sat Feb 04, 2012 3:19 pm

*Mahi* wrote:Go on @nafistiham :)

:lol: I am a know nothing about programming.But, in the last national i saw my name in the news paper on the $11^{th}$ place just doing some of the analyticals.must be some typo.... :lol:

$8.$How many non-prime numbers$\leq 40$ which are divisible by the sum of their prime
factors? (7)
Ans :
the numbers will be $p^k$ where $p,k\in \mathbb{N}$ and $p$ is a prime
so, they are $2,4,8,16,32,3,9,27,5,25,7,11,13,17,19,23,29,31,37$
so the number is $19$

$12.$ One of the questions in this paper (both analytical and programming) has it's
mark written in binary. Can you identify it? Write the problem number. (10)
Ans :
analytical part $7,12$ and Programming Problems $4$
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
Using $L^AT_EX$ and following the rules of the forum are very easy but really important, too.Please co-operate.
Introduction:
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Re: BdIO-2012 Dhaka

Unread post by novice » Sat Feb 04, 2012 8:01 pm

:lol: I am a know nothing about programming.But, in the last national i saw my name in the news paper on the $11^{th}$ place just doing some of the analyticals.must be some typo.... :lol:
It was not a mistake! Just find 2/3 hours free some day and learn just how to code. The rest is up to your problem solving skills :) Just learn how to code with C language,from beginning to array/strings and a whole new world of problems will open up for you!

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