## Solving regional BdOI Dhaka-2013

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nafistiham
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### Solving regional BdOI Dhaka-2013

Informatics regionals are over. So, I suggest we should talk about the problems. I would be glad to post those problems, if they were not that much big.
I wish someone could post any pdf version of the problem set.
$\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0$
Using $L^AT_EX$ and following the rules of the forum are very easy but really important, too.Please co-operate.

kfoozminus
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### Re: Solving regional BIOC Dhaka-2013

there was same question in all divisions, and hey... it's BdOI, not BIOC(it actually means Bangladesh Informatics Olympiad Committee)

এক জন যদি একটা করে পোস্ট করে তাহলেই তো দশটা হয়ে যায়... i'm posting number 10(oh yeah! i liked it!)

$10.$ $n$ pigeonholes are kept side by side in a row. you want to put pigeons in some of the holes in a way that for every $k$ consecutive holes there will be exactly $m$ holes with a pigeon. There shouldn't be more than one pigeon in a hole.

For example,
For $n=4$, $k=3$, $m=2$, a solution can be $PP.P$(here $P$ means a pigeon and $.$ means a hole), but $.PPP$, $PPP.$, $P.P.$ or $PP..$ aren't solutions.

$1.$ write a general formula to find the number of solutions for $n$, $m$ and $k$
$2.$ $n=5$, $k=3$, $m=2$
$3.$ $n=1000000000$, $k=30$, $m=25$

*Mahi*
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### Re: Solving regional BIOC Dhaka-2013

kfoozminus wrote: $10.$
Hint:

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

*Mahi*
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### Re: Solving regional BdOI Dhaka-2013

You can get the PDF question paper in this topic.

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

Labib
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### Re: Solving regional BdOI Dhaka-2013

Anyone help me with the solution of number 6??
Please Install $L^AT_EX$ fonts in your PC for better looking equations,
Learn how to write equations, and don't forget to read Forum Guide and Rules.

"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." - Sherlock Holmes

*Mahi*
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### Re: Solving regional BdOI Dhaka-2013

Labib wrote:Anyone help me with the solution of number 6??
The solution is quite straightforward.
1. Send the largest element of the $k$ element stack at the end with at most two 'reverse' moves.
2. Continue with the $k-1$ element stack.

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

Fatin Farhan
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### Re: Solving regional BdOI Dhaka-2013

how can i start learning programming

*Mahi*
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### Re: Solving regional BdOI Dhaka-2013

Fatin Farhan wrote:how can i start learning programming
Use $L^AT_EX$, It makes our work a lot easier!