ChallaAjay's blog

By ChallaAjay, history, 2 hours ago, In English

Hi everyone,

Unpopular opinion: below roughly 1700, Codeforces is mostly a pattern-recognition contest, not a problem-solving contest.

Look at what actually shows up in Div. 2 A to D:

Prefix sums, two pointers, binary search on the answer “Sort it and greedy” Parity, gcd, and constructive tricks you either know or don’t DP states that are variations of problems you’ve seen before

People who’ve seen 500 problems solve them fast. People who haven’t get stuck, no matter how smart they are. That makes the rating at this level partly a measure of how much you’ve grinded, not how well you think.

The counterargument (and I half believe it): patterns are skill. Recognizing which tool fits is exactly what good problem solvers do, and the same people climb to 2000+ anyway.

So where do you stand?

A) Early rating is mostly memorized patterns

B) It’s real thinking, and grinding just builds that skill

C) It’s a mix, and the balance changes as you climb

Reply with your letter, your current rating, and one problem that convinced you. I’m especially curious whether people above 2000 think the answer flips at higher levels.

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2 hours ago, hide # |
 
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Auto comment: topic has been updated by ChallaAjay (previous revision, new revision, compare).

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115 minutes ago, hide # |
 
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i vote for A

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95 minutes ago, hide # |
 
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how about pupil or specialist?

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    75 minutes ago, hide # ^ |
     
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    pupil and specialist mostly, thats the range i mean. 1200 to 1600ish. above that it starts to need real ideas

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80 minutes ago, hide # |
 
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A, 1637, and there are so many problems that have solutions of "just sort/do smth with min and max". 2236A for example. It's 800, yes, and it gives the vibes of "iykyk" type problem.

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    64 minutes ago, hide # ^ |
     
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    yeah exactly, the “iykyk” ones are what i mean. if you know it its 2 mins, if not you waste 30. did you solve 2236A on your own or after seeing the trick?

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      40 minutes ago, hide # ^ |
       
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      I did solve it on my own, and funnily enough it really took 2 minutes lol. I'm sure there are better examples of "iykyk" problems, but I already forgot them.

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48 minutes ago, hide # |
 
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I believe C. My reasoning for this is if i give a reasonably smart person who has never done cp but knows how to program a list of every trick for cp, its unlikely they will be able to solve div2 c. Evidence for this is you are allowed to use google for codeforces rounds yet a large portion of participants cannot solve div2c. I don't think its pure thinking because coming up with completely novel ideas to solve each problem is just not feasible. I don't think I could reconstruct binary search within two hours had I not known it and thats one of the simplest "common" algorithms.