Dear Codeforces community,

We are pleased to announce a call for problem proposals for the second edition of the North African Olympiad in Informatics (NAOI), which will be hosted this year by Libya.

As the number of submitted tasks remains insufficient, we have extended the submission deadline to March 31st.

If you enjoy designing challenging and original problems, we warmly invite you to share your ideas with us. Your contribution will help shape an exciting competition for students across the region.

For submission details, please visit:
https://naoi2026.ly/tasks/

We look forward to receiving your proposals.

NAOI 2026 Organization Committee

NAOI 2025 is after 3 weeks, and we've just sent the participants who will represent Libya

here is the list of the official teams: link, and I'm making this blog to have all the participants who will compete in NAOI 2025 with their codeforces handles

if you have the details for your country's participants, write them in a comment like this:

Contestant Name (codeforces handle if it exists) 1st time at NAOI, X attempts left

let's write all the contestants in this blog!

let's start with my country contestants:

• Mousa Aboubaker (Mousa_Aboubaker) — 1st time at NAOI, 0 attempts left
• Albara Abdulhafith (Albara_Abdulhafith) — 1st time at NAOI, 0 attempts left
• Fadel Elsenusi (Fadel_Elsenusi) — 1st time at NAOI, 3 attempts left
• Ahmed Albakoush (ahmed1611) — 1st time at NAOI, 0 attempts left
• Abdulrahim Khoja (Khoja) — 1st time at NAOI, 0 attempts left
• Yousef Jaeda (rixiepixie) — 1st time at NAOI, 3 attempts left

good luck to all the participants, and if you got your country details, share them in a comment and I will update the list regularly

when I was solving this problem, I thought that Igor can go directly to any cell in any row above his current row as long as the Euclidean distance between that cell and his current cell is less than or equal to $$$d$$$

but in the last minutes of the contest, I realized that he can only go to any cell in the row that is exactly above him if he can reach it

with this, I found the solution for the problem faster and I got AC

now, I'm wondering, how to solve this problem if Igor can go to any row as long as he satisfies the constraints ?

for example, in the second testcase, Igor can go from the last row to the first row as mentioned in the image above

the result should be 70

2  3  0 2
0 10 10 0
0 35 0 35

what is the optimal solution for such a problem ?

I'm looking forward to see your ideas and solutions, and thanks ^_^

as you can see in my profile, I have 365 days in a row in codeforces

before a year, I started CP with a simple programming background

I always wanted to start CP and learn DSA and how to implement them in problems, how to think better, how to be a good problem-solver!

until the opportunity shined

our national Olympiad (LOI) started in the previous year, as the first time since 10 years ago, and I find this opportunity is the best for me to start CP and learn DSA

My beginning

We took a course before the LOI, and my first coach was Hussien_Ibrahiem, I'm really very proud to be one of his students, he taught the first step, and showed me the road, I learnt a lot of him, he was the one that made me to understand what is CP, and how beautiful is this world!

He stayed with me along to way until the IOI, and I'm really happy that I met him in IOI, thank you coach on all your efforts <3

LOI Champion

After we took the first course in LOI, it was time for the qualification contest, I was really happy that I finished the contest in 18 minutes!

now, it is time for the final contest, LOI!

I don't know how to express my feelings when I was afraid that I won't win LOI when I were stuck on the last problem and couldn't get the last subtask

I completed the first three problems with perfect result in 19 minutes, but I took 1 another hour to solve the last problem with the prefect result!

I was really happy then when I got the first place and being LOI24 champion ^_^

Libya IOI24 team

After the LOI and in May, we took an intensive training (for the top 20 places in LOI) for a month, then we took a summer camp for a week, after that, we had the team selection contests, I completed the first contest in 1 hour and 9 minutes, and completed the second one in 26 minutes

and again, I got the first place and qualified to represent my country ^_^

and I'm happy for being expert at this training <3

thanks for EOI organizers and their help, and thanks for the coaches in the training and the camp

Ahmed_Aladdin Magdy98 JoeSherif Ma7moud7amdy Hussien_Ibrahiem

and thanks for Errichto and Huawei for IOI24 camp!

IOI

We competed at IOI for the first time since 10 years ago! it was a beautiful feeling to compete in an international Olympiad <3

to be honest, I did very bad in the first day and placed 310 out of 362 :( but in the second day, I followed a specific strategy rather than the random one in the first day, and I'm happy that I placed 210 out of 362 in the second day ^_^ I don't remember what was my final place in the ranking (the website isn't working anymore :( ), but in IOI stats, my rank is 276 I'm really happy for living such an experience like IOI in my life! and I'm happy that I currently have the highest score in IOI of my country <3

and what is the best thing at IOI ? the best thing is that I met with amazing people the Libya IOI team had a preparing camp with the Egyptian IOI teams, and I'm happy that I met smart people like them!

AbdelmagedNour Octagons Ahmed57 ismailfateen TAhmed33 Hexagons MinaRagy06 NourWaelAli

it was a dream, but I'm really happy to meet them, and I'm really happy to meet the legend Bakry and take a picture with him <3

it was so nice to meet Phantom_Performer in real life, he is such a nice person! he was the first person that I asked about how to prepare for IOI, and he did tell me how he started and how to learn and think, I'm really happy to know such a person!

another person that I'm really happy to know and met at IOI, is bashkort, I knew him from APIO24 and asked him about a problem in that competition, and then I asked him how to improve myself for IOI, and he did give me a lot of information, how to follow a strategy to gain as much as possible at IOI, resources to learn from, and he was always giving me advices to improve, I'm really happy to know him <3

I'm hoping for the best in the next steps, and I hope to meet more nice persons in my CP journey! let's go ahead for CM ^_^

if you complete reading this post, here, take a heart <3

good luck to you all ^_^