Hello everyone!

There is yet another Codeforces round. Now it is the 5^{3}-th one.

The round will run for both divisions by classic rules of Codeforces format.

Points are standard: 500-1000-1500-2000-2500.

Round was prepared by Ripatti , Alex_KPR , Gerald , Aksenov239 , RAD , Delinur .

Good luck!

UPD. Round is ended.

Winners of div1:

1. Petr

2. tourist

3. SergeyRogulenko

4. bmerry

5. UESTC_Nocturne

Winners of div2:

1. gflegar

2. cupidon4uk

3. arbesfeld

Petr is only who solved all 5 problems in the first division. No one solved all 5 problems in the second division.

UPD. Editorial.

0.001

_{2}from 1000_{10}What you want to say? I'm not understanding.

1/8 * 1000 = 125

be careful! 5^3 is meaning something... maybe this is hint for some tasks ))

This is an algorithmic contest Mr. Sherlock Holmes :P

Can we suppose fixed scoring, as it is not specified?

It is already specified that the points are standard ->500,1000,1500,2000,2500 .. So no dynamic scoring

Nothing is obvious here.

但愿不坑爹

Please comment in english :)

Very tough problem set .. I could not understand what problem B wanted . :(

I think that examples were clear...

I think this case will help you to understand this. Correct answer is 2.

Looks like I will get more than minus 100 rating for birthday present T_T such bad luck T_T

Regardless, Happy Birthday! :)

I'm try to solve 4 problems..., and solve only one :/

C is very annoying :) Got 9 WA's and still don't know what's wrong with my solution.

I had a WA 4 when I checked for line-circle intersection instead of segment-circle.

Ehhhhh, the same mistake here.

C was very fun (I didn't get it though). Thanks for a good problem set!

any idea for it?

the thng was tht the entire process was totally recursive..

so if 1 value matches the sequence the rest will follow..;)

simply simulate the expt1 till u do not exceed t..

after tht both will take same number of steps....

ans is n-i+1 where i is no. of steps to reach t

P.S.: be careful not to output -ve..:P

Um, no. We were talking about division one C.

ohh....my bad..

sorryy....

In problem B in div 2, we just have to find number of circles(out of 4) which are not intersected by any other circle. Am I right ?

Please help me someone.

Yes, you're right, my young padawan.

You have to check for every circle from each pair that it lies either in smaller of the other pair or outside bigger of the other pair. Checking only intersection is not enough as you can face a situation when a circle lies between 2 others ( exactly in the ring), so the color is not changed from white to black or vicer versa).

You should find the number of circles that are not intersected by the other 'disc'. For a circle in disk 1, simply checking intersection with both circles of the other disc is not enough. For example, the 1st disc may lie entirely inside the black region of the other disc, in which case there are no circle-circle intersections, but the number of contours is 2.

can you add tutorials?

tomorrow

your's tmmrw never comes..:P

Today is Dragon Boat Festival. Happy Dragon Boat Festival!

Also, today is Alan Mathison Turing's 100th birthday.

I can add to your wonderful list that today there is another one celebration in Saint-Petersburg called Scarlet Sails show ("Алые паруса" in Russian). It's the holiday for all school-leavers. However, that event gathers not only them, but a lot of citizens and visitors of Saint-Petersburg.

Strange !! People here vote for colors not for content .. Even I wished him in my blog and got a lot of negative votes .. Sad but truth...

The problem with your post in my opinion is: How can Turing be happy on his birthday when he has passed away many years ago ?!! So, wishing a happy birthday to him may not make that much sense.

Editorial ?

It seems a spell error? Winners if div1 -----> Winners of div1:

yes, thanks