Where is Rajat De? - Codeforces

6 years ago, # ^ |

-32

LoOoOoOoOOLoOoOOOoOOLooOOoOoOL. LMAO. ROFL. There are so many ways to learn new things, not just through CP. Well, indians are obsessed with good competitive programmers because CP is one of the "only" ways that they can get into a big tech firm. This has been mentioned by quite a few indians already. This is quite a stupid way to think. But if your country requires you to think that way in order to survive...what else can you do?

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acraider

6 years ago, # ^ |

+17

Some might feel so, however, i don't feel that everybody do CP in india to get in Big firms. That is a consequence of mere practice you get from this sport. I feel that You were rejected by smaller firms too and hence are free enough to spill such nuisance in the Comments of Codeforces. Well thanks for entertaining the community with your "LoOoOOOoooOooLoOoOoooOooOLooOooOOoL. LMAO. ROFL."

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6 years ago, # ^ |

-10

LoOoOoOoOOLoOoOOOoOOLooOOoOoOL. LMAO. ROFL. I rejected all indian companies who offered me jobs because I felt that their organization were filled with imbeciles who thought that "CP" actually makes you a programmer.

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acraider

6 years ago, # ^ |

+12

Thank you a lot for helping us making our environment Clean!!

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LanceTheDragonDuckSicker

6 years ago, # ^ |

-88

Loololol. LMAO. ROFL.

Rajat isn't the best, he isn't even an IGM. Hundreds of people are better to learn from. Indians should learn that they suck and start following other non-Indian competitive programmers.

It's clear that IAmNotGood has an obsession with rajat to create this blog post. He should stop his obsession and practice more. I have confidence that once he follows someone like Radewoosh, he will be better than rajat.

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Dazzler

6 years ago, # ^ |

-8

shit comment

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RedNextCentury

6 years ago, # ^ |

+55

What's the point of following someone way better than you (like Radewoosh), you won't be able to solve the problems he solves, you need to go up step by step

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Draco_Malfoy

6 years ago, # ^ |

+21

And that's why you should follow step_by_step!

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6 years ago, # ^ |

+127

I don't think that means you should obsess over him like crazy. If he doesn't want to do competitive programming things right now then let it be so. People can take breaks for various reasons, note that this doesn't mean they won't be successful in their next major contest. Also there are many ways that one could be practicing so that it doesn't show up. For example when I was in Petrozavodsk I only did the contests there and upsolved them. For an outside observer it might seem like I was doing nothing at all.

If he wants to explain he can do so but right now this behaviour is almost stalkerish. This also goes for people who obsess over Radewoosh, tourist, Benq or anyone else.

Also do you guys seriously learn by reading someone else's code? In my opinion that is one of the worst ways.

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6 years ago, # ^ |

Looking though stronger participant's code can give you new ideas and implementation tricks. Sometimes you can find solutions that are so short, clean and self-explanatory that reading them gives you understanding of both: the ideas behind solution and the way to implement it.

Yes, usually it does not give you any proofs or explanations why this solution works. And some of solutions can be very large and contain some complicated logics, so understanding the ideas becomes really hard. But sometimes it is definitely worth looking though others' solutions.

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AdiZer0

6 years ago, # ^ |

I think, just asking idea of this code from author of code is better than understanding idea of code by yourself.

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6 years ago, # ^ |

Sadly, that's not always possible.

Original author might be too busy or inactive, so he will not answer you. Or sometimes you want to ask about the code he submited few years ago, in this case he might not even remember that he ever solved this problem or he might have changed his coding style a lot and does neither remember the idea of submited solution nor understand his old code quickly.

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aryaman

6 years ago, # ^ |

I can barely understand code I wrote yesterday, how am I going to learn from other people's code ;-;

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6 years ago, # ^ |

+14

Uh, even in this case looking though others' code might help you to develop coding style that will make your code understandable for you.

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6 years ago, # ^ |

← Rev. 2 →

+42

Is it worth the effort?

The main hard part about competitive programming is thinking and you aren't going to get better at that by looking at the end result of someone else's thinking process. Particularly one that was written in a hurry and contains things that would, in other contexts, be called "unholy" or "a monstrosity".

I also see a very real danger here. Suppose that Grandmaster Alice implements a variation of a standard-ish algorithm. There are a lot of special cases but Alice, having a very good understanding of the algorithm, realizes that half of them don't actually happen in this particular problem and skips implementing them. Later, Specialist Bob reads Alice's code, doesn't realize that half the cases are missing and tries to apply the algorithm in some other problem. He gets WA, becomes extremely frustrated. He then proceeds to post the code in Codeforces under the title "wy dose this giv WA" with no explanation whatsoever.

This is not some hypothetical story either. Do you know how many people do not understand how std::memset works? I have seen a lot of people getting bugs because of memset(arr, 1, sizeof(arr)); or similar statements in code (where arr is an array of ints). I bet a lot of them saw memset(arr, 0, sizeof(arr)); or memset(arr, -1, sizeof(arr)) in some experienced user's code and got a very wrong idea about what memset does. Please, try writing

int arr [10];
memset(arr, 1, sizeof(arr));
cout << arr[0] << endl;

What is the output? What if we replace int by long long?

Implementation tricks are neat, but there are not so many and I've managed to pick up quite a few without reading other people's code regularly.

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John_Cena

6 years ago, # ^ |

-17

Can you explain why this behavior??

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gatecse2018

6 years ago, # ^ |

+24

is it very hard to google "how memset works"?

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6 years ago, # ^ |

← Rev. 4 →

Yes, learning to think by analysing someone's result of thinking process is not always a great practice. But in my opinion, this is not a rare case when you can reconstruct the whole solving process just by looking over the proper solution.

This process is similar to reverse-engineering. You open the code and think in a way like "Okay, here we can see standard-ish algorithm name implemented, probably with some modifications. So we can assume that problem can be solved with it. Author used usual ints here and long longs here, so we can see that this part of calculations can be done in ints and this part likely cannot. But author ommited implementing this and this special cases. So we can assume that they cannot be achieved in this particular and similar problems (and test cases are strong enough, of course)..."

It is like you are given a bunch of hints for this problem and combining them with your own ideas might be enough to understand the solution and implementation.

Yes, to do that you must be familiar with algorithms used, be familiar with special cases that usually occur there and data structures used. Of course, it is only your responsibility to prove exactly why every line and token in code works here and analyse when it will work and when it will not.

But the benefit of this method is that you see the exact code that is responsible for this. And sometimes you think "Yes, this is short, cool and clear. If I can prove why it works I will definitely use this next time instead of 50 lines of own-invented code."

From my experience I've had few of similar moments when I've looked through one's code. Last time it happened to me that I remember clearly was Radewoosh's solution for problem 101611I - Infinite Gift from gym 2017-2018 ACM-ICPC, NEERC, Московский четвертьфинал.

Problem I - Infinite Gift spoiler alert

I'm not saying that this is the best learning method. Of course not. Probably this method will not be suitable for everyone. But it is easy to see when you are getting lost for few minutes in one's code and cannot understand anything, in this case you can try looking through another solution or stop doing that for this problem.

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I_love_Hoang_Yen

6 years ago, # ^ |

+33

I think what you described mostly apply to cases where reader just blindly copy paste and don't really try to understand what's going on in the code. e.g. In your memset example, only lazy people will just use the function without knowing what it does. These people will fail no matter how they learn.

Some examples where reading code helped me in the past:

When I was young I did not know how to implement binary search. After reading several different implementation I finally found one where I understood and use since then.
For many problems I found solutions better than mine. Especially for easy problems, just knowing the problem can be solved in a certain way is a big hint on how to solve it.

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KalasLavas

6 years ago, # ^ |

You copy template ¬_¬

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6 years ago, # ^ |

+13

I don't understand what you're trying to say.

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adderall

5 years ago, # ^ |

-11

Realest comment here

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6 years ago, # |

-27

LoOoOOOoooOooLoOoOoooOooOLooOooOOoL. LMAO. ROFL. I know why he stopped using his actual handles. Probably because he received too many PMs from his fellow countrymen of the form "hello sir. please tell how to become red in one year."

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teja349

6 years ago, # ^ |

+73

Hello Sir. Please tell me how to involve myself at unwanted business.

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torpedo11

6 years ago, # ^ |

← Rev. 3 →

+21

Hello sir, Please tell me how to be an attention whore.

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6 years ago, # ^ |

-32

LoOoOoOoOOLoOoOOOoOOLooOOoOoOL. LMAO. ROFL. You just have to be indian.

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xXxxXXxxxXXXxxxXXxxXx

6 years ago, # ^ |

+11

Hey, can you please stop doing such stupid things?

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hugdunga

6 years ago, # |

+75

You are Rajat DE

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thehumbleguy

6 years ago, # ^ |

+43

Plot thickens

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panipuri8

6 years ago, # |

+42

Aah, I knew someone was going to accuse Indians of being obsessed stalkers.

Where is Errichto? — Codeforces with 340 upvotes.

Uhm? Hypocritical much?

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