How to become an Expert on Codeforces | Tips and Topics for each Rating from Newbie to Specialist

Summary

In this video, Priyan Agarwal offers a comprehensive roadmap for advancing from a novice to an expert on Codeforces. He emphasizes mastering a programming language, understanding time and space complexity, and learning essential math concepts. For different rating levels, he suggests specific topics and strategies, such as binary search for pupils and dynamic programming for specialists. Agarwal also provides tips like focusing on implementation skills and avoiding irrelevant topics, and recommends resources like CP Algorithms and his CP31 problem set for structured learning.

Takeaways

• 😀 Priyan Agarwal provides a roadmap for Codeforces users to progress from newbie to expert.
• 🎯 The video targets three main rating groups on Codeforces: Newbie, Pupil, and Specialist.
• 🛠 For newbies, mastering a programming language and understanding time and space complexity are crucial.
• 🧠 Newbies should focus on learning basic math concepts, recursion, and inbuilt functions of their programming language.
• 📈 Tips for newbies include not rushing through topics, building strong implementation skills, and staying motivated.
• 🔍 Pupils should concentrate on advanced topics like binary search, number theory, prefix sums, and greedy algorithms.
• 🌟 For pupils, tips involve solving ad-hoc problems, participating in contests, and applying learned concepts.
• 📚 Special attention is given to mastering binary search and greedy algorithms for those rated as pupils.
• 🏆 As a specialist, topics like two pointers, advanced number theory, dynamic programming, and graphs become critical.
• 📘 Tips for specialists include proving approaches, reading blogs for deeper understanding, and avoiding irrelevant topics.
• 📝 The video also mentions resources like CP Algorithms and the CSS problem set for further learning.

Q & A

What is the main goal of the video presented by Priyan Agarwal?

The main goal of the video is to provide a comprehensive roadmap for individuals to improve their coding skills on Codeforces, with the aim of advancing from a newb to an expert level.

Why is it important to master a programming language according to the video?

Mastering a programming language is crucial because it enables you to implement 90% of the logic that comes to your mind without needing to rely on external help, which is essential for competitive programming.

What is the significance of understanding time and space complexity in competitive programming as per the video?

Understanding time and space complexity is significant because it allows you to write efficient code. Efficiency in coding is judged through these complexities, which is a key aspect of competitive programming.

What are the three important tips given for newbs on Codeforces?

The three tips for newbs are: 1) Do not run after advanced topics too soon, 2) Focus on building strong implementation skills, and 3) Do not get disheartened by the initial challenges and focus on building fundamentals.

Why is binary search advanced emphasized for pupils on Codeforces?

Binary search advanced is emphasized for pupils because it involves understanding monotonic functions and is a fundamental technique that can be applied to many problems, making it a crucial skill to master.

What is the role of number theory in advancing from a pupil to a specialist on Codeforces?

Number theory plays a pivotal role as it involves mastering concepts like Sieve of Eratosthenes and the Ukkonen algorithm, which are often the basis for many problems on Codeforces.

How does the video suggest improving implementation skills for competitive programming?

The video suggests improving implementation skills by focusing on solving a lot of problems, ensuring that when a logic comes to mind, one should be able to code it out efficiently.

What is the advice for pupils on Codeforces regarding the habit of solving ad-hoc problems?

The advice is to get into the habit of solving ad-hoc problems, which do not require specific topics but rather logical thinking, to enhance problem-solving skills.

Why is dynamic programming considered the most important topic after binary search in competitive programming?

Dynamic programming is considered the most important topic after binary search because many problems on Codeforces are based on dynamic programming ideas, and mastering it is essential to becoming a competitive programmer.

What are some additional topics that can increase the chances of becoming an expert on Codeforces as mentioned in the video?

Some additional topics that can increase the chances of becoming an expert include graphs, trees, binary lifting, segment trees, and range query data structures like Fenwick or Sparse tables.

What is the significance of the TLE Eliminators course mentioned in the video?

The TLE Eliminators course is significant as it provides a structured learning environment with live classes, curated practice problems, and instant doubt support, helping to teach relevant topics and improve problem-solving skills for competitive programming.

Outlines

00:00

💻 Path from Codeforces Newbie to Expert

Priyan Agarwal introduces a roadmap for aspiring competitive programmers aiming to improve their ratings on Codeforces. He highlights the current scenario where the majority of participants in India are below a 1300 rating and emphasizes the need to progress to the 'expert' level. The video is structured to guide viewers through the journey from a beginner ('newb') to an expert, providing specific advice and tips for each rating level. The speaker outlines the importance of mastering a programming language, understanding time and space complexity, and learning about data structures and algorithms. Special attention is given to the concept of recursion and building a strong foundation in mathematics.

05:01

📚 Advancing from Pupil to Specialist on Codeforces

The speaker discusses the next steps for those who have progressed beyond the newbie stage on Codeforces. For 'pupils' with a rating above 1000, the focus shifts to mastering advanced topics like binary search, number theory, prefix sums, and greedy algorithms. The importance of binary search is underscored, with a recommendation to solve numerous problems to gain expertise. Number theory is also emphasized, with suggestions to learn advanced concepts like sieve algorithms. The speaker provides practical tips, such as focusing on implementation skills, not getting disheartened by initial difficulties, and the value of participating in contests to apply learned concepts.

10:03

🎓 Transitioning to Specialist and Beyond on Codeforces

As the discussion moves towards higher ratings, the speaker congratulates those who have achieved the 'specialist' level and outlines the advanced topics they should tackle. These include two-pointer techniques, advanced number theory, combinatorics, and dynamic programming. The speaker stresses the critical nature of dynamic programming for competitive programmers and encourages solving a significant number of problems in this area. Additional topics like graphs, trees, and advanced data structures are suggested for those aiming even higher. Tips for specialists include proving approaches, reading blogs for independent learning, and avoiding irrelevant topics that do not contribute to becoming an expert.

15:05

🚀 Final Steps to Expert Level on Codeforces

In the concluding part, the speaker provides targeted advice for those close to achieving an 'expert' rating on Codeforces. The guidance includes solving problems within a specific rating range, utilizing resources like CP Algorithms and the CSS problem set, and focusing on problem-solving rather than memorizing solutions. The speaker also introduces a personal resource, the 'cp31' sheet, which curates problems based on Codeforces ratings. The video ends with encouragement and a structured approach for viewers to follow, ensuring they have a clear path from beginner to expert in competitive programming.

Keywords

💡Codeforces

Codeforces is a competitive programming platform where participants solve algorithmic problems and are rated based on their performance. In the video, it serves as the central theme, with the presenter providing a roadmap for viewers to improve their ratings from 'newbie' to 'expert'. The platform is mentioned multiple times as the context for the advice and strategies shared.

💡Competitive Programming

Competitive programming is a mental sport where participants try to solve complex algorithmic problems within a limited time. The video is focused on guiding viewers through the journey of competitive programming on Codeforces, emphasizing the importance of learning specific algorithms and strategies to excel in this field.

💡Rating

A rating in the context of Codeforces refers to a participant's skill level, which is determined by their performance in contests. The video discusses the importance of improving one's rating and provides strategies for moving from a 'newbie' to an 'expert' rating, which is a significant aspect of competitive programming on the platform.

💡Programming Language

The choice and proficiency in a programming language is crucial for competitive programmers. The video emphasizes mastering one programming language, suggesting that a participant should be able to implement 90% of the logic on their own, which is a foundational skill for success in competitive programming.

💡Time and Space Complexity

Time and space complexity are measures of the efficiency of an algorithm in terms of the time it takes to run and the memory it uses. The video stresses the importance of understanding these complexities to write efficient code, which is a key aspect of competitive programming as it allows for faster and more resourceful problem-solving.

💡Recursion

Recursion is a programming technique where a function calls itself to solve smaller instances of a problem. The video highlights recursion as a fundamental concept that is extensively used in competitive programming, particularly in solving problems that can be broken down into similar sub-problems.

💡Binary Search

Binary search is an algorithm used for finding an item from a sorted list of items. It is mentioned as an important topic for those who have reached the 'pupil' level on Codeforces. The video suggests mastering binary search, including its advanced applications, as a step towards becoming a better competitive programmer.

💡Number Theory

Number theory is a branch of pure mathematics dealing with properties and relationships of numbers. In the video, it is presented as a topic that 'pupil' level participants should delve into, including advanced concepts like the Sieve of Eratosthenes and the Euclidean algorithm, which are used to solve problems related to prime numbers and divisors.

💡Greedy Algorithms

Greedy algorithms are a problem-solving approach that makes the locally optimal choice at each step with the hope that these local choices will lead to a global optimum. The video advises learning and mastering standard greedy algorithms and solving problems that involve non-standard greedy ideas, which is a common approach in competitive programming.

💡Bit Manipulation

Bit manipulation involves directly operating on the individual bits of an integer. The video suggests that 'pupil' level participants should learn and master various bit manipulation techniques, as they are crucial for solving certain types of problems in competitive programming, particularly those involving optimization and efficiency.

💡Dynamic Programming

Dynamic programming is a method for solving complex problems by breaking them down into simpler subproblems. It is highlighted in the video as an essential topic for those at the 'specialist' level on Codeforces, emphasizing that mastering dynamic programming is key to becoming a competitive programmer, as many problems on the platform are based on this concept.

Highlights

Priyan Agarwal provides a roadmap for improving on Codeforces from a newb to an expert.

90% of people in India are rated below 1300 on Codeforces, indicating a need for better competitive programming skills.

For newbies, mastering a single programming language is crucial.

Understanding time and space complexity is essential for writing efficient code.

Learn about inbuilt functions in your programming language like C++ STL for quick implementations.

Focus on basic math concepts and modular arithmetic for a strong foundation in competitive programming.

Recursion is a fundamental concept that is widely used in various topics.

As a newbie, avoid advanced topics and focus on building a strong foundation.

For pupils on Codeforces, binary search advanced is a crucial topic to master.

Number Theory and prefix sums are important topics to level up from a pupil to a specialist.

Greedy algorithms are key in competitive programming and require mastering standard greedy ideas.

Bit manipulation is a significant topic for those approaching specialist level on Codeforces.

Solving ad-hoc problems helps in developing logical thinking without relying on specific topics.

Participating in contests and learning from unsolved problems is a recommended practice for pupils.

For specialists, two pointers and sliding windows techniques are essential for optimizing binary search problems.

Advanced number theory and combinatorics are key areas to focus on as a specialist.

Dynamic programming is a must-master topic for any competitive programmer.

Basic graph and tree algorithms are beneficial for those aiming to be experts on Codeforces.

Reading Codeforces blogs and editorials is recommended for independent learning at higher levels.

Avoid learning irrelevant topics that are not necessary for reaching expert level on Codeforces.

CP Algorithms and the CSS problem set are valuable resources for learning and practicing.

Targeting problems within a 200-point range of your current rating on Codeforces is a strategic approach.

Transcripts

hi everyone welcome back to the channel

my name is priyan Agarwal and in this

video I am going to give you a complete

road map to go from newb on code forces

to expert 90% people in India today are

less than 1300 rated on code forces now

that's a very very shocking number

because this tells us that so many

people in India are trying out

competitive programming they're getting

started with it but very very few people

are actually getting to a good enough

level and a good enough level in

competitive programming is actually

something like an expert so in this

video I going to go in a specific order

first of all I will talk about what

should you do if you're a newbie then

what should you do if you're a pupil and

then what should you do if you're a

specialist on good forces right so I

will not be just talking about the

topics that you should learn I will also

be giving you tips along the way that if

you are in this rating range what are

certain tips for you so just watch every

single minute of this video very very

attentively make notes of it if you want

to so let's get started by talking about

what should you do if you're a newb on

code forces so first of all you should

Master a programming language okay

become very very good at one programming

language but in that one programming

language you should be so good that if a

logic comes in your mind and if you want

to code it out you should be able to

implement 90% stuff on your own and 10%

of it you are allowed to Google next you

should learn about time and space

complexity because see if you talk about

data structures algorithms and if you

talk about competitive programming the

most important thing is not just writing

the code but writing an efficient code

how do you judge this efficiency you

judge the efficiency of your code

through time and space complexity next

you should learn about you know inbit

Stu stuff in your programming language

for example if you look at C++ there is

this thing known as C++ STL standard

template library now standard template

Library contains a bunch of functions

that you know help you implement some

stuff very very quickly similarly for

programming languages like Java python

there are their own resources now once

you've mastered a programming language

you know how to judge the efficiency of

your code and you also know some

important inbuilt functions in your

programming language this is the point

where you start focusing on maths now

for the subtopics for maths I would

recommend you to learn about basic high

school level math concepts like you know

hcf LCM primes divisors multiples right

you should also refer to this very

important topic of modular arithmetic

after you done learning these basic math

concepts right what you should do is

that you should Master this one concept

which is known as recursion okay

recursion is one concept that is going

to be used in a lot of topics as you go

forward so this is the entire set of

topics that you should learn as a newb

again a lot of importance on recursion

and a lot of importance on building the

fundamentals right now let me also give

you three important tips if you're a

newb on code forces the very first thing

is that don't run after topics there is

no need for you right now to learn

Advanced topics like greedy dynamic

programming graphs trees all of these

there will be a time when you will get

to learn all of these topics the second

tip is that you know you should focus a

lot on building your implementation

skills like if there is a logic that is

coming into your mind you should be able

to implement it easily right and the

third tip is that you know don't get

disheartened at this moment I understand

that when you're starting your

competitive programming Journey you will

see that everyone around you is doing so

well while you are stuck at this newb

rating range and you're not able to

progress but that's absolutely fine okay

right now just focus on building your

fundamentals and once you're done doing

that you will see that when you are

attempting quod forces contest you will

be able to solve problems right and you

will be able to get to a pupil range

very very soon now let's talk about what

are the topics that you should learn if

you're a pupil on code forces if your

rating on code forces is greater than

1,00 the very first most important topic

right now is binary search Advanced why

am I saying binary search Advanced and

not just simple binary search because

this topic also involves binary

searching on answer like you will see

that your answer in certain problems are

having a monotonic function right you

can study about all of these topics if

you don't know about them right now just

note it down monotonic functions right

but this is one topic that you should

absolutely Master right you should spend

a lot of time on this solve a lot of

problems even if you solve 50 problems

on binary search Advan it is going to be

absolutely worth it the next topic that

you should look at is number Theory now

while you were a newb on code forces you

would have learned the basic concepts

like primes divisors all of these things

but at this point you need to level up a

bit when you're pupil on code forces you

should focus on topics like C of

eratosthenes ukan algorithm these two

topics are very very important and you

will see that there are so many problems

which are just simple variations of ukan

algorithm and C fosis so make sure you

master these topics the next topic that

you should Master is prefix sums now I

know prefix sums looks like a very easy

topic but let me tell you there are so

many variations of prefix sums there are

so many variations where you know you

have to use a C++ standard template

Library function or a C++ STL data

structure in order to optimize your

prefix some queries so make sure you

solve a lot of variations on prefix sums

just knowing the basics of prefix sums

is not enough try and find a lot of

problems which involve variations of

this after you're done mastering prefix

sums the next topic that you should look

at is greedy algorithms again absolutely

very important okay because if you talk

about competitive programming it is not

just about applying standard data

structure standard algorithms into

problems a lot of problems are going to

be based on Grey ideas and this is also

going to help you in contest when you

look at the second problem or even the

third problem in most Cod forces contest

a lot of them are based on greedy ideas

now in terms of greedy algorithms there

are two things that you need to focus on

first is mastering all the standard

greedy algorithms okay there are going

to be a list of standard greedy ideas I

can even you know share some resources

in the description of this video you can

look at all those algorithms and master

them these are all standard greedy

algorithms other than that you also need

to solve a lot of non-standard greedy

algorithmic problems basically you go on

to code forces you know you put the tag

of greedy and you solve any random

problem in that problem you might

require a standard greedy idea or you

might have to think about a greedy idea

on spot right the next topic that you

should Master if you are either a higher

pupil or almost a specialist on code

forces is bit manipulation now I have

personally created a video around bit

manipulation tricks on the YouTube

channel of T eliminators so you should

check it out it contains around 10 very

very important bit manipulation

techniques right so make sure you check

that out and that would help you open up

your mind about bit manipulation now let

me also give you three important tips if

you're a pupil on code forces firstly is

to get into the habit of solving ad hoc

problems What are adhoc problems these

are problems which don't require a

specific topic but only a logical you

know mind like just looking at a random

problem you realize that okay it can be

logically solved like this but it does

not really involve a particular idea or

a particular you know data structure or

an algorithm so these are adog problems

get into the habit of solving these

random problems okay the second tip is

to get into the habit of absolving

contest what is the meaning of absolving

basically whenever you attempt a contest

after that you look at those problems

which you weren't able to solve and you

try to figure out the solution either

you do that on your own or you look at

the solution of those problems and try

to learn the concepts which are being

used in these problems the third tip

that I'm going to give you is to you

know give enough contexts like at this

moment I can understand that it gets a

little overwhelming that you're learning

so many topics but make sure that you're

not just learning you're giving enough

contest and you're applying those

learned Concepts in contest problems

right because just learning a topic is

not enough you need to solve problems on

it and you need to solve problems on

those topics within contest now in case

you are somebody who requires some

support in order to learn all of these

topics in a structured manner then let

me tell you about my course called tle

eliminators that I've been running from

April 2021 so it's been 3 years since

I've been running that course we have

taught more than 5500 programmers

through that course already now this

entire course you know is divided into

four levels so for somebody who is at a

particular level in their competitive

programming Journey they can choose to

join a level and learn only those

relevant topics so first of all you get

live classes on all of these topics

right every single week we have around

one to two live Theory classes and we

teach you all of these Topics in a very

structured manner secondly we provide

you with curated practice problems on

all of these topics that we've taught

you for example if I teach you dynamic

programming for maybe 3 weeks then in

these three weeks I am going to give you

two to three problems every single day

now in case you're stuck on any practice

problem from the course you get

dedicated video solution where we talk

about the exact intuition involved how

do you think apart from this if you're

stuck on any practice problem from or

outside the course we provide you with

instant doubt support now what happens

in doubt support is that we have a team

of around 30 to 40 experienced

competitive programming mentors these

mentors are already experts and

candidate Masters on code forces and

they help you solve these problems in

which you stuck like you could come up

with a debugging problem you could come

up with a problem in which you require

some hints and overall you know you get

to learn a lot from the experience of

these mentors and apart from that there

are other pretty cool features uh you

know you can go and check out our

website to explore them uh one thing

that I want to mention is that tle

eliminators is a live course right so

every 3 months we launch one single

batch and in one single batch we run all

of these level 1 2 3 4 parall so you

know you can go on to our website and

check out when is the next course coming

up and if you're interested you can sign

up for that let's talk about what should

you do if you're a specialist on code

forces now first of all before I talk

about all the topics that you should

learn let me congratulate you if you've

become a specialist on code forces it

means that you've already beaten 90%

people in India okay now that's a big

number because what this means is that

if you were just targeting competitive

programming for probably placements or

internships if you're going to sit in an

online coding test you are going to

perform better than 90% people in India

the very first topic that you should

learn as a specialist is two pointers

and and sliding windows so two pointers

is one technique you know that can help

you optimize a lot of your binary

searching ideas like most of the binary

searching problems that you solve on

arrays and subarrays you will see that

they can be converted into two pointers

and they can be further optimized the

next topic that you should learn is

Advanced number Theory now if you've

become a specialist I am assuming that

you already know the basics of number

Theory you know Concepts like modular

arithmetic a bit about ukan algorithm a

bit about primes devisers C fosies this

is the point where you learn about FMA

theorem Oilers theorem right you also

learn about Advanced things like finding

modular inverse and this is also the

point where you focus a lot on

combinatorics because going forward when

you look at the third problem or the

fourth problem in code forces contest a

lot of problems are based on

combinatorics the next topic which is

the most important in competitive

programming after binary search is

dynamic programming okay this is one

topic that you should Master you cannot

call yourself a competitive programmer

if you're not good at dynamic

programming because I can tell you that

you know if you're solving a random

problem on code forces the chances that

it is based on a dynamic programming

idea are insanely High okay and if

you're a specialist on code forces don't

expect yourself to become an expert if

you cannot Master dynamic programming so

spend a lot of time on dynamic

programming make sure you solve you know

at least 50 to 100 problems on this

topic you can start by you know looking

at standard uh dynamic programming

problems this you can find on CSS

problem s and also on code forces blogs

once you mastered the standard dynamic

programming problems go on to code

forces start solving random DP problems

put a rating filter of 1 1600 or 1,700

on code forces and apply you know the

problem uh topic tag of dynamic

programming and start solving a lot of

problems because mind you as you go

forward if you look at graphs if you

look at trees if you look at other

Concepts you will see dynamic

programming being used extensively right

so make sure you master this topic right

now itself and when you are doing

dynamic programming also you know focus

a bit on DP with bit masking and now I'm

going to mention some topics that even

if you don't do it's fine but if you do

them then the chances of you becoming an

expert become even higher the very first

topic is graphs now I am not asking you

to learn Advanced graph algorithms and

solve very Advanced graph problems no

learn about depth for search breadth for

search connected components how you can

apply shortest path algorithms try to

solve a lot of basic graph problems

basic graph problems means they involve

basic ders Sals they involve basic

properties of graphs after you're done

learning the basics of graphs also learn

the basics of trees because nowadays it

is getting more and more common that you

will find uh you know trees problems

being asked in the third or the fourth

problem in a lot of code forces context

so learn about the basics of trees uh

what comes in the basics first of all

basic traversal like depth for search uh

you know handling some subtree queries

like uh pre-computing some information

for every single subtree of a tree then

learn about binary lifting binary

lifting is very very important it helps

you calculate stuff like lowest common

ancestor of two nodes right and it also

helps you do a lot of other stuff if you

want to go a bit higher and if you want

to go and learn some more advanced

topics I would recommend learning about

segment or learning about any you know

range query data structure like fenry or

maybe Spar stles like you can learn the

basics of these you don't have to go

into the depth of them again now let me

give you some tips if you've already

become a specialist on code forces the

very first thing is to start proving

your approaches now you can't be in that

mindset that I am going to guess an

approach and I'm going to just submit it

on code forces and expect it to pass no

that's not going to happen start proving

your approaches when you're thinking an

approach before coding it make sure you

know why it works the second tip that

I'm going to give you is to start

reading start reading code forces blogs

or blogs on other competitive

programming platforms start reading

blogs on CP algorithm's website at this

moment you should try and become a lot

more independent like you can go for

video Solutions you can go for paid or

free courses but if you go for reading

that is going to help you a lot because

going forward when you become expert or

even if you become a candidate Master

you are not going to find enough

resources to learn Concepts you are

going to have to refer to code forces

blogs you are going to have to refer to

editorials of problems right so get into

the habit of reading and don't get into

the habit of Simply watching a video

solution the last tip that I want to

give you as a specialist is to avoid

learning irrelevant topics what are

those irrelevant topics these are things

like you know uh Cent decomposition on

trees heavy light decomposition on trees

learning about KMP algorithm learning

about Z algorithm and you know learning

about Advanced things like flows square

root de composition these are are things

that you don't need in order to become

an expert now let me mention some

resources that you can refer to in order

to become an expert and learn these

topics the very first resource is CP

algorithms this is one thing that you

cannot ignore another thing that I would

recommend you is to start solving CSS

problem set so CSS problem set contains

you know a bunch of topicwise problems

and these are very standard and the most

important problems for every single

topic so if you're learning dynamic

programming for example go and start

solving problems on the CSS problem set

if you're learning about graphs or if

you're learning trees there's an entire

section for all of these topics so go

and start solving problems on CSS

problem set if you're a new or a pupil

on code forces you might not find

relevant topicwise problems on CS

problem set so for this there is an

entire section on introductory problems

go and solve that entire section there's

an entire section of searching and

sorting go and solve this entire section

of searching and sorting when you come

to the specialist rating range this is

the point where you can look at specific

topics like dynamic programming graphs

trees range queries right and one more

thing that I want to recommend in this

entire journey of you becoming an expert

is that if you are xrated on code forces

if your rating is let's suppose 12200

Target problems from x - 200 to x + 200

based on code forces difficulty so if

you have 1200 on code forces solve

problems from 1,000 rating all the way

up to, 1400 on COD forces now if you're

looking for a resource to you know solve

rating wise problems then you can refer

to my cp31 sheet this is a resource that

I've constructed by spending 80 plus

hours reading 50 00 plus problem

statements and handpicking only those

problems which are the most interesting

and the most important for Ratings from

800 all the way up to 1600 on code

forces so that was it for this video

guys I hope you found it insightful and

you now have a structured way to go from

either newb pupil or specialist to an

expert rating on COD forces in case you

want to get more depth on you know uh

what are the subtopics that you should

be learning for every single topic here

I have made a dedicated video for that

and you can check that out as well