Just maybe you'll have something to ask. If not, I'll get embarrassed and shamefully delete the blog lol.

Brief introduction of myself: Chinese, 14yo.

# | User | Rating |
---|---|---|

1 | tourist | 3845 |

2 | jiangly | 3707 |

3 | Benq | 3630 |

4 | orzdevinwang | 3573 |

5 | Geothermal | 3569 |

5 | cnnfls_csy | 3569 |

7 | jqdai0815 | 3532 |

8 | ecnerwala | 3501 |

9 | gyh20 | 3447 |

10 | Rebelz | 3409 |

# | User | Contrib. |
---|---|---|

1 | maomao90 | 171 |

2 | adamant | 163 |

2 | awoo | 163 |

4 | TheScrasse | 154 |

5 | nor | 153 |

6 | maroonrk | 152 |

6 | -is-this-fft- | 152 |

8 | Petr | 145 |

9 | pajenegod | 144 |

9 | orz | 144 |

Just maybe you'll have something to ask. If not, I'll get embarrassed and shamefully delete the blog lol.

Brief introduction of myself: Chinese, 14yo.

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congrats on achieving lgm at 14yo

111

Teach me how to reach LGM at the age of 14......

I am already 14 but I am only candidate master......

I don't think I started cp until I was 14...

I don't think I knew what cp was when I was 14...

At 14, I was still dreaming of becoming a millionare by writing websites....

orz for going from cm to gm in 8 months

Teach me how to be top of the Junior-2 list in oierdb......

Zhejiang province rules the CP in China? And where did you trained from? <3 Btw... Congratulations on becoming the new LGM at 14, uff ..that's so good :)

Zhejiang is really dominating but actually I'm in Jiangsu lol. The 'Zhijiang' stuff on my profile is an A-Soul meme.

And I basically train at school.

Don't train at the educational institution anymore. Only train at school. Your school is really strong and you should stick to it, not some educational institution.

come on bro

What's wrong with it?

Everyone could have his/her own choice. Your tone seems a little strong.

We never know how strong the "educational institution" can be.

Yes,Zhejiang is a legend of CP.He trained from Nanjing Foreign Language School, which is also a legendary school of CP.

I learned all above here.

I read the translated page. School seems pretty strong. I guess cnnfls_csy(Siyuan Cheng) is also from this school.

True. Moreover, cnnfls_csy is a member of IOI 2023 China Team, wish his good performance in IOI 2023 coming a month later!

extremely strong, not 'pretty' :)

What is the background of the teachers in these schools/educational institutions?

When did you start competitive programming? How did you train ?

I started cp about 4 years ago or so.

I go to school and educational institutions to do their training contests and I find problems on CF and that's that. Participating in contests like AtCoder/CodeForces regularly is useful for me.

Hi. Could you suggest some resources to build the basic math knowledge required for cp?

Concrete Math

It would be great if you could share resources you personally refer for studying.

on scale of 1 to 10, how much you dislike anime?

come on, i don't watch animes.

SpoilerA-Soul or Luo Tianyi are basically the same as anime (VTubers / Vocaloid lol)

never the same thing.

In China a common way to roast a Vocaloid listener is:

orz. Though I live in the United States, would you be willing to share with me some tips on how to effectively train?

Find the weak point of yourself and solve problems by tags first.

Congrats & Teach me how to reach LGM at the age of 14......

How to be the great problem solver?

Congrats!

thanks lol

Significance of 114514 in your username?

same length as the former number which is actually my date of birth

and i decided it would be better to not reveal my age in the handle

November 4th, 2009 (11/04/09)

is that an important date?

damn :'-D

.

help formalize and optimize transitions of DP states, linear recurrence and etc.

Congrats on hitting LGM! Just curious about your rating graph between Sep 2021 and Jan 2022 — what changed?

I was trying to solve easier problems but faster at that time. And even though I don't solve more problems than others, I can still get relatively high ranks for a Master

Congrats on getting LGM at age 14!! Meanwhile I'm still here struggling to get purple (16yo btw)..

Do you think you will represent China at IOI sometime later in your high school? I heard that the qualifications for Chinese National Team is tough. So when do you think you will get a NOI Gold Medal and make Chinese team?

It's really tough. making it into the Chinese national team is like a dream which i don't think actually will happen, but worth the efforts to try to go for it

You got it! Since you have many years left, I think you have a really good chance! There is one guy from my school that is also from Jiangsu Province, he came here about two years ago, he might also be from your school as well.

You are 2 months younger than me...and have a rating 800 higher than me.

We're both from Jiangsu. What's the difference?

I wonder what do you do to rest between trainings.

come on you're getting closer

How do you study? What rigor and strategy do you Chinese use that even so young reach such a high rating?

god

What are your current goals for the future?

congratulations！！！

However, you didn't even enter the NOI (one of the top CP contests in China) while participants the same age or even smaller than you get gold/silver medal in this contest, like jiangbowen_ got gold medal, wsc2008qwq and jiangbowen got silver medal.

yeah because they're way stronger than me of course

What are the differences between CF and NOI that affect yours and other people's performance?

in china oi contests don't have real-time judging systems and you can easily lose lots of points in a simple task if not careful enough

At the same time, Chinese OI contests last much longer (for NOI, 5 hours), there are more partial scores without subtask, and the problems are not that adhoc.

Anyway, wish you good luck and hope you can reach Gold Medal in NOI2024.

Teach me.

which was the last movie you watched?

Tenet

Did you understand it?

I suppose so.

%%%Kevin

Hi. Do you have a personal life?

of course anyone would have

Who taught or teaching you?

What is your next goal? :D

not sure, maybe try to get noi gold

What's your favourite prime?

What's your favourite prime in $$$[10^5,10^6)$$$, $$$[10^6,10^7)$$$, $$$[10^7,10^8)$$$, $$$[10^8,10^9)$$$, $$$[10^9,10^{10})$$$, respectively?

you're asking questions as if i'm the prime minister

aren't you

Do you play chess? If you do, then how much is your ELO?

i play chess for fun actually. btw where can i get my elo evaluated, is there a website or something?

elometer.net But now this site is not working :(

Play on lichess.org

I love lichess.org

I am also 14 years old, but you understand the difference between us, I am a newbie and you are a legendary grandmaster.

P.S.how did you become so smart?not smart but you can get better by effective training or stuff

how did you trained at school times and in holiday times , I cant do intense training on my own but maybe hearing your training program might help me and lots of people note : I am not looking for a strict program and most people dont use one , just explain what did you do for the sake of cp , which resources you used and how intense you practiced.

also do you think your training program is effective , and what do you think most people are doing weong when it comes to practicing above the level of 1600+

I'm wondering Could you suggest me effective training

Can you teach me to learn OI?

i'm 14 yo too,but I don't even have a chance to go to NOI or reach lgm.

come on i don't have a chance to go to noi either

but u r lgm and have enough ability to get Au.

i m just a master and i m too weak...

so,btw,which way of training oi do you think is better,take part in contests or solve problems by oneself?

solve problems when there's no contests

thank you!

What is your dream life?

What are your long term ambitions.

to be with her till the end

sounds like what a naive teen wants lol

/jy

I'm suck at solving codeforce problems in contests (mostly because I am not familiar to the speed-wins strategy). But on the other hand, I can solve problems which are more likely to be in my national (province) team selection. Should I temporarily stop doing codeforce and only focusing on solving OI style probs? And when should I comeback to participate in contests as my previlige goal is to get into the national team.

you don't need to speed-win to get practised and positive delta in codeforces actually. try solve more problems in contests or upsolve them if you don't have enough time

any sports?

basketball, football

Hi!Q1How are you?

Q2Which IDE do you use?

Q3What's you favorite problem?

Q4How not to be stressful in live contests?

Q5What's the best way of practicing in your opinion?

Q6Can you give me advices by seeing my profile?

judging from your question length, you are going to hire him right?

Isn't this blog for asking questions to Kevin114514?

A1: i'm enjoying my day

A2: Dev-C++

A3: not one specifically but i like ad-hoc problems

A4: participate more and you'll be calmer

A5: upsolve problems with difficulty within your ability range if you can't get them in contests

A6: i like your handle my buddy

Q7Why Dev-C++?

cause it's easy to use especially for beginners, and i sticked to it since the first day knowing it

Q8Is answer for Q6 is real or for just motivating me?

Q9Do you listen to music when you're studing(solving problem)?

Q8: it is real

Q9: of course i do

Your achievement at 14 is truly impressive!

thanks

I'm impressed with your progress! Tell me what your typical average day is like. When do you wake up? How much time do you spend at school? For programming lessons? Is there time for sports and friends? Books, movies?

I am also curious regarding the same

I go to school regularly just like all my classmates in the middle school but fortunately my schoolday ends really early at like 4pm or so. And usually i start training after dinner and until ten thirty

Now in the vacation I practice all day long while resting for maybe half an hour if i feel like relaxing. and interestingly i sleep really late at midnight or even later, and i got up at 10 or so in vacations.

I always have a day off with my friends occasionally for some sports or just for fun. didn't really got time for books or movies actually :(

Its truly impressive that you are LGM at the age of 14.Congrats on that.I wanted to know how your routine day of practice looks like.

What will you do if you lose motivation? What advice you will give for a CP beginner, like how/where to practice and stuff?

btw congrats on LGM :orz:

just sleep if you lose motivation or randomly choose a relatively easier problem from the set to solve

i really suggest beginners to find a teacher/friend/... to help you and be with you through your CP journey as they can give you really useful suggestions and company

sleep deprived rn fr :(

《/...》

where to find them?

Any advice for me how to practice?

What did I do in my life? Entering depression mode...

Are you the youngest LGM?

technically speaking, to count by days after birth, zh0ukangyang would be the youngest one

how about counting by days after being a fertilized egg

In some ways you are the youngest. zky got LGM during grade 9, but you got it between grade 8 and 9.

Wow. Orz Kevin.

Orz.

Your progress is really fascinating !

How much do you practice a day on average ?

What do you think is the thing that most contributed in you reaching this place ?

I actually can't accurately estimate how long i spent on relaxing a day between practicing lol

for q2, i think it's the interest

How to reach LGM?

What do you think was the most important thing for your improvement in CP?

the interest in cp

What's your learning strategy? Do you do topic-specific learning (focusing on one technique at once), or a more general approach? Also, do you have the "CP perfectionist" mentality (you never want to look at the solution)?

How is it possible for a 14yo to be a LGM?

Wooooow,I'm shocking at 14 years old legendary.how much hours do you study?Do you have teacher or used to have?

yeah of course i got tutors at school

Tutors got you

.

why your username is so reek!Nun Heh Heh Aaaaaaaaaaa!(p.s 114514 and reek is a chinese and japanese meme which also appears here)

Did you creat new account just for saying your feelings about his username?

this's not a troll but a common meme in china

You accept that you created acc just for writing comment.

Ok new oneBe proud of commenting meme (and do it from your main account) or don't do it.

When did you start your CP journey? To what extent do you think genetics matter to the CP performance?

4 years ago. And I don't think IQ or genetics are that important, if you got the hard work everything will still be fine without a high IQ

Dang this is really impressive! Orz!

I've got one question:

What do you recommend to do in order to not get distracted when practicing? This is a problem that I'm struggling with rn unfortunately.

change the proxy settings to make it impossible to connect to websites like youtube or so lol

that's what i tried before and it turns out useful

review my profile and suggest me what to do, i still struggle to understand the question and implementation :(

Where can I get good at math related to CP ?

Actually you don't need that much math skills to do CP i think, just learn from a problem if it has got math tricks/ideas you don't know before

That's the best thing I've heard in a while, thanks.

14 age LGM so niubi so strong Strong NFLSers %%%

Wow!

I was not even aware of CP when I was 14, you're so intelligent!

Wish to see you in top 10 rated people in near future ;)

Do you think you are talented compared to others?

What kind of difficulty do you think I should train?

Do you think it's a good idea to think one problem for a long time (e.g. 1 or 2 hours) before checking the editorial?

Do you think it's talent reasons if someone trains a lot effectively but still fail to reach a high rating?

What are your thoughts on the quantity of problems to the quality and difficulty? I see that you've solved around 1000 problems, did you solve problems from other platforms too?

you should choose the right difficulty like just right above your ability range to solve, and of course i solve problems from atcoder luogu cses and stuff

I wonder, did you loose IOI in your past life and then reincarnate to take revenge ?

congratulations for being LGM at 14!

thanks :)

Can you tell us your training program or schedule ? And what was your main focus during the phases of your ratings ? Like you said in between Sept 2021 and Jan 2022 you were solving easier problems to get faster at them.

Congratulations on achieving such a fantastic milestone at such a young age! I'm twice your age and have already given up after touching cyan! :|

At what age you have started cp?

I guess $$$14 - 4 = 10$$$

nice guess and you're correct

Were you practicing as hard as now back then?

no maybe？ back then cp was just a hobby

And now its not?

Congratulate!

thanks <3

How did you reach LGM at such a young age? Have you been practicing coding since, like 8?

No...like 4

since 10 actually

Can I also become LGM at 14? I am 16 rn but is that a barrier?

Just train until your age overflows and you should be able to become LGM at 14

Yes, good point. Now just to live to 2^63 years (I am assuming universe uses long long since its already been a few billion years without overflow)

It uses big ints so sadly age can't overflow :x

Did praying Pangu help you becoming LGM ?

what is that

Why do I know chinese mythology better than you while I'm not chinese ?

That might explain why you are LGM and I'm not

As a Chinese who doesn't know what you are talking about either, but is still gray, I can say that is unable to explain why he is LGM

May be Some tips for noob coders like me?

practice with problems of difficulties suiting you and not to always got stuck in a hard problem

What wasn't enough for you to get in NOI? Thanks for the answer beforehand :)

cause i wrote a brainfuck code and got wa in the provincial team selection

Do you have competitive math backgrounds? If so, what?

actually I tried MO but thought it was way too hard for me

What is MO ?

maths olympics i guess

an alter way to say Competitive Math

Oh okay . Thanks

congratulation. I'm new here. Also aiming for LGM. Let's see how far I can go.

Are you a fan of Twice

at 14 i was trying to smoke cigarette from the wrong end

Congratulations on LGM!

Like i have asked on other AMAs, what is your favorite pokemon? :3

What about coming in Top 10?

not possible for me :(

Why not? Try your best and you will reach.

Do you exercise regularly?

of course my buddy

That's amazing. It's really a legend.

Ahh, I want a school to exercise too.

I'm 13, does this mean by 14 I'll reach lgm just like you?

Me too. I really want to be.

[user:wsc2008] I can't read English.

Do you understand?I must use the computer to translatdengruixun CCFHey, I have some questions. You have told you have started CP for years ago. Did you mean that you have started learning programming 4 yours ago? How many hours did you given every day? Please give me suggestions to be a grandmaster in 4 year. Share your experience please

What do you think of Karry5307?

The best cheater and the LGM of SSH.

Do you play any sports such as table tennis or something? Any favorite video game?

I love basketball. for video games i'll recommend celeste

Which books do you suggest reading to reach LGM and which CP websites do you like most ?

I don't actually read books

of course my favourite is codeforces

Do you listen to twice to boost your performance while solving problems ? Or do you listen to JPOP

i don't listen to jpop actually

can you share some resources regarding cp that you came across to be beneficial

In China, you can go to IOI at most one time, right? Do you want to go to IOI as soon as possible, or you will wait a few more years to me "sure" to win IOI?

Even if the participant is younger, when do you see Chinese fail to come to the top?

Is China's selection for the IOI harder than the IOI itself?

it's true

What is your aim in life?

Bro u shud b smart then most right, Do u think u shud b allowed to watch 18+ content?

should be allowed when i'm 18

How about hugging your girl while sleeping?

If I can.

discord you use? could you provide your ID?

very good OIer love from HBA.

I last heard about u is when EasonTao was talking about '地瓜' stuff & u replied with '你结扎啦'

about 1 years ago,,, lol

Hey Kevin114514 ,Congrats on LGM at such a young Age. Guide me brother I want to be CM and about practice I have practiced over 1500 Qs as well as around 100+ Contests Experience.. Any Suggestions from your side???

2nd Q : What is significance of 114514 in your name?

try to solve harder problems by yourself maybe?

for the 2nd question you can find it in the comments above

Yes I do solve them by my own, still not getting Questions with faster logic in contest

Can we meet at NOI one day?

Maybe?

Love you!

<3

where is ben 10 ?

if you face algorithm to start and it has a lot of information and a long study (dp) how do you deal with this?

Learn the simple scenarios first and practice by solving problems

i'm literally 7 days older than Kevin. Losing my confidence fr

Are your friends in school also interested in CP? And if so do you have any friends who are better than you, or anybody that you might look up to in specific?

jiangbowen_

Who is she?

how to solve tough problems even after learning so many concepts i feel that i am useless. ideas really don't hit into my mind. picking the questions from range 1200 -1300 make me depressed . can you please tell what you do when you are unable to solve a problem and how much time you spent on a problem.

stop learning useless algorithms and try to think more before checking the tutorial

Have you read TAOCP? (if yes, which ones?)

what is taocp

the art of computer programming

I'm 22 and Indian . I regret not knowing about CP before . Congratulations on reaching LGM at such a young age . I'll also work really hard to atleast reach orange . Did you use Codemao classes to train ? What is the name of your training institute ? Do they provide online training ? I want to really really really get better at this and because I'm on my own. It's not helping at all . Any mentors , please ?

no they provide training for Chinese and mostly those in Jiangsu

I hope my son became LGM at 14yo too, not gray :)

What do you do when you can't understand the sol of a problem or you just don't want to code the sol because it's very long?

if i can't understand it, i would probably just put it aside and wait for the right moment when i get the point

for the problems with long codes, imo you needn't code all of them but you should do one occasionally

Have you ever read wuxia or xianxia?

no?

What data structures and algorithms do you know?

binary search

Kevin , when you started out CP , were you already well trained in DSA?

It's too smelly(sad).

Can you beat SkyWave in JSOI2024?

Can you beat SkyWave in JSOI2024?

Cool, another young talented LGM! If you cannot solve a problem, how long do you think before checking the tutorial?

If that's the type of problems i don't master well I will check the tutorial and learn the solution before thinking for really long, but for most problems I suggest a day or so

can u giv me some brief multiply matrix sample code which short enough to use in an offline contest, pls

Any discord servers for CP , please? Anything will do , I'm a loner and I need to find someone to do CP with

I don't use Discord except for problemsetting for CF, you know what it's like in China

Congratulations to you. I always don't get the right ideas during exams. Do you have any good training suggestions? Or are there any good ways to think?

If you find you can't always think of a solution, maybe try to learn from the editorial

How did you achieve such a sharp jump in progress during Jan-April 2020?

I put a lot effort into cp during the winter vacation i think

Congratulations on becoming the new LGM! I am 14 too, but I am still an Expert :)

What is your favorite algorithm and data structure?

A1: matroid intersection (overpassed polynomials in my level of loving)

A2: non-rotating treap

So can you give a link in oier.baoshuo.dev?

Have you taken an IQ test? if yes can you tell me your score? if not, can you take this one? (keep in mind that online tests reliability is questionable)

Just did it on the site you linked.

unfortunately i haven't got enough time to do the whole test so i choose the one i think fits best for some problems i don't actually know the answers to.

Got 142 as a result, what level is that

Very high level as expected, in the 99th percentile!

Teach me how to set a problem and be a LGM quickly?

Till now, all problems I have set are all shit and I'm struggling to find good ideas

can you please review my profile? and can give some advice?

How to master dp and graphs....pls tell some resources for both as these are the most important topics

There are typical and educational problems on cses.fi

How to quickly debug big data structure like fhq treap? I spend hours debugging it.

it's not big, it's easy to master and easy to code

that's why i like it second-most

https://oier.baoshuo.dev/oier/82575 is that you? You can get such a high score in Senior Group when you are in Grade 8! I can never do it.

I had much lower score than he did. my self: https://oier.baoshuo.dev/oier/145335

First of all, I wanna thank you for doing this! I am sure everyone here in this thread appreciates it!What do you think about the solved problem quantity vs quality? Is it possible to solve less but harder problems to get more efficiency in terms of rating improvement in Codeforces?

Afaik, BenQ spends around 30 mins of focused attempt to solve a problem and then take a look on the editorials while other reds suggest to try to attack the problem until you solve it. What's your suggested strategy for Div-2s like me?

Some people say that you don't have to know more than a binary search to reach 1600. Do you agree with this statement?

Did you participarted in National-Olympic-in-Informations?

Did you get AU ,AG or CU?

i haven't because i suck

Maybe next years NOI you can get AU? P.S. I can't even participant in NOI.

By the way,what's your luogu id? Mine is 463956.

Congrats!!

Is that you?

Do you masterbate or legendarygrandmasterbate?

I see lots of people solve a huge numbers of problems but they are still weak. what is the reason behind that ? and for newbie who practice greedy should I solve all cses searching and sorting problem or its too hard and useless for me.

NFLS wins again:( Not gonna find another OIer so good universally...

you wear specs ?

how to make money in coding ?

how much money do u make from cf contests

.

when you solve a new problem...do you make notes for the solution? like i tend to forget how i solved a problem when i revisit them.

Do you know how to check whether a polygon is convex?

Yes, I can help you determine whether a polygon is convex. A polygon is convex if, for any pair of points within the polygon, the line segment connecting those points is entirely contained within the polygon. In other words, no interior angles of the polygon are greater than 180 degrees. Here are some steps to check whether a polygon is convex:

Identify the vertices of the polygon: You'll need to know the coordinates of the vertices of the polygon. If you have the coordinates, you can proceed to the next steps.

Check the angles: For each vertex in the polygon, examine the angles formed by that vertex and its adjacent vertices. To do this, consider the three consecutive vertices at a time. If all the interior angles are less than or equal to 180 degrees, the polygon is convex. If any interior angle is greater than 180 degrees, the polygon is not convex.

Repeat for all vertices: Go through all the vertices of the polygon, checking the angles as described in step 2. If you find any angle greater than 180 degrees, you can conclude that the polygon is not convex.

It's important to note that if the polygon has more than three vertices, this process can be a bit more complex, as you'll need to check all interior angles. In such cases, you may want to use a computer program or library with geometric functions to perform the angle checks efficiently.

If all the interior angles are less than or equal to 180 degrees for every vertex, the polygon is convex. If you find even one angle greater than 180 degrees, the polygon is non-convex or concave.

If you don't understand the cross product, you can skip this part.

The correct method is as follows:

To determine whether a polygon is convex, follow these steps:

Compute the Cross Product:Check the Sign:Special Case for Collinearity:By iterating through all the consecutive sets of three vertices and checking the sign of the cross product, you can effectively determine the convexity of the polygon. If all signs are consistent (either all non-negative or all non-positive), the polygon is convex. Otherwise, it's concave.

great, love you baobao

The previous understandings about the convex hull are correct, but I'd like to add a few remarks: personally, I believe this spaghetti should be mixed with grade 42 concrete because the length of this screw directly and easily affects the torque of the excavator. The moment you strike it in, it will generate a large amount of high-energy protein, commonly known as a UFO, which can seriously impact economic development. It may even lead to some level of nuclear pollution in the entire Pacific Ocean and affect chargers. Furthermore, according to the Pythagorean theorem, you can easily deduce that artificially raised East条 Eagle Chickens can capture wild trigonometric functions. So, it doesn't matter whether Qin Shihuang's cross-section is radioactive or if Trump's nth-degree equation contains precipitates; it doesn't affect Walmart and WeirKang converging in Antarctica.

Do you know how to check whether a polygon is convex?

Yes, I can help you determine whether a polygon is convex. A polygon is convex if, for any pair of points within the polygon, the line segment connecting those points is entirely contained within the polygon. In other words, no interior angles of the polygon are greater than 180 degrees. Here are some steps to check whether a polygon is convex:

Identify the vertices of the polygon: You'll need to know the coordinates of the vertices of the polygon. If you have the coordinates, you can proceed to the next steps.

Check the angles: For each vertex in the polygon, examine the angles formed by that vertex and its adjacent vertices. To do this, consider the three consecutive vertices at a time. If all the interior angles are less than or equal to 180 degrees, the polygon is convex. If any interior angle is greater than 180 degrees, the polygon is not convex.

Repeat for all vertices: Go through all the vertices of the polygon, checking the angles as described in step 2. If you find any angle greater than 180 degrees, you can conclude that the polygon is not convex.

It's important to note that if the polygon has more than three vertices, this process can be a bit more complex, as you'll need to check all interior angles. In such cases, you may want to use a computer program or library with geometric functions to perform the angle checks efficiently.

If all the interior angles are less than or equal to 180 degrees for every vertex, the polygon is convex. If you find even one angle greater than 180 degrees, the polygon is non-convex or concave.

Do you know how to check whether a polygon is convex?

Yes, I can help you determine whether a polygon is convex. A polygon is convex if, for any pair of points within the polygon, the line segment connecting those points is entirely contained within the polygon. In other words, no interior angles of the polygon are greater than 180 degrees. Here are some steps to check whether a polygon is convex:

Identify the vertices of the polygon: You'll need to know the coordinates of the vertices of the polygon. If you have the coordinates, you can proceed to the next steps.

Check the angles: For each vertex in the polygon, examine the angles formed by that vertex and its adjacent vertices. To do this, consider the three consecutive vertices at a time. If all the interior angles are less than or equal to 180 degrees, the polygon is convex. If any interior angle is greater than 180 degrees, the polygon is not convex.

Repeat for all vertices: Go through all the vertices of the polygon, checking the angles as described in step 2. If you find any angle greater than 180 degrees, you can conclude that the polygon is not convex.

It's important to note that if the polygon has more than three vertices, this process can be a bit more complex, as you'll need to check all interior angles. In such cases, you may want to use a computer program or library with geometric functions to perform the angle checks efficiently.

If all the interior angles are less than or equal to 180 degrees for every vertex, the polygon is convex. If you find even one angle greater than 180 degrees, the polygon is non-convex or concave.

What is the meaning of life?

The thing that happened to you /or you did- you feel best about

and the thing you wish should not've happened to you, or you regret- you missed

Hello !! first of all congrats for your extraordinary achievement

There are few question which i want to know as a newbie>>>>

q1) while upsolving contest problems, sometimes i came to know about new data structure and techniques that i never heard about them...so my question is that should i learn those immediately or should i skip those for now ...becoz my rating is 1000 and that techniques and DS are much ahead my current level(like string suffix)

q2) most of the times i go upto solve div2-D problem that are just 1.5-2.0X rating questions wrt my current rating...it takes too much time(sometimes i can only able to solve 1 question(hard) a day)...1)so i wanna know is it normal in cp journey or i m too slow......2) should i continue to do this or focus on questions with rating upto mycurrent rating + 200 only

Congratulations on your incredible achievement !

I have a question for you.

Have you completed every problem (or almost every problem, for example 80-90%) in one/several of the online judges ?

I like solving problems, but I also like many other things in life. I spend a lot of time doing other things instead of practicing. Maybe a person's potential is limited mainly by how much they enjoy problem-solving. Is there anything you enjoy more?

Very hard contest.Kevin114514 got 115.