Hi Codeforces

I'd like to announce 18th HourRank round! The contest will be held on 16:00 UTC Thursday, March 2 2017. Contestants will be given 4 problems and 1 hour to solve. You can sign up for the contest here. Top 10 winners will receive a HackerRank T-Shirt.

HourRank 18 is prepared by me(svanidz1). I want to thank whole Hackerrank team, especially Shafaet for coordinating and Wild_Hamster for testing the tasks.

The contestants are ranked by score. If two contestants gets same score, the person who reached the score first is ranked higher

Wish you good luck.

UPD1: Score distribution : 15-30-50-75. Contest starts in less than 2.5 hours. All problems will have partial scores.

UPD2: Contest is over. Congratulations to winners:

1. krismaz

2. LHiC

3. uwi

4. anta

5. I_love_Tanya_Romanova

6. vintage_Vlad_Makeev

7. rajat1603

8. arsijo

9. chemthan

10. gvaibhav21

Thank you for participation.

Hi Codeforces !

I'd like to announce the fifth HackerRank HourRank round! The contest will be held on 16:30 UTC Monday, Feb 1 2016. Contestants will be given 4 problems and 1 hour to solve them. You can sign up for the contest here. Top 10 winners will receive a HackerRank T-Shirt. The contest is rated for all users.

HourRank 5 is prepared by me(svanidz1). I want to thank whole Hackerrank team, and especially Shafaet, wanbo and malcolm for testing the tasks.

Wish you good luck.

UPD1: Score distribution : 20-40-50-80. Contest starts in less than 5 hours. All problems will have partial scores.

UPD2: Contest starts in less than 1.5 hours.

UPD3: Contest starts in less than 15 minutes.

UPD4: Contest is over. Editorials are published. Congratulations to winners:

1) Endagorion

2) uwi

3) Egor

4) LayCurse

5) Nezzar

6) I_love_Tanya_Romanova

7) Gullesnuffs

8) akashdeep

9) MikeMirzayanov

10) nhho

Thank you for participation.

Hello Codeforces !!!

I'd like to announce the second HackerRank HourRank round! The contest will be held on 16:00UTC Monday, 2 November 2015 . Contestants will be given 4 problems and 1 hour to solve them. You can sign up for the contest here. Top 10 winners will receive a HackerRank T-Shirt. The contest is rated for all users.

Contest is prepared by me(svanidz1). I want to thank whole Hackerrank team, and especially Shafaet, wanbo and malcolm for testing the tasks.

Wish you good luck.

UPD1: Score distribution : 25-40-60-90.

UPD2: Contest starts in less than 3 hours.

UPD3: All problems will have partial scores, Contest starts in less than 1.5 hours.

UPD4: Contest starts in less than 5 minutes.

UPD4: Contest is finished. Editorials are published. Congratulation to winners:

Top 5

1) Endagorion

2) uwi

3) bardek

4) mgch

5) I_love_Tanya_Romanova

Thank you for participation.

Does there exist an algorithm, for a given sequence to find a sub-sequence with minimum possible xor? Or at least an algorithm finding a subsequence of xor==0?