https://codeforces.com/recent-actionsCodeforces - Recent actions - Powered by AtomRSSAtomRSScontact@atomgroup.dev (AtomRSS)enSat, 08 Aug 2026 05:59:00 GMT5Okay, any one who opened this and upvoted will good luckhttps://codeforces.com/blog/entry/155785?#comment-1383922https://codeforces.com/blog/entry/155785?#comment-1383922Sat, 08 Aug 2026 04:38:35 GMTKeep commenting and your comments magically gain more attention when you're expertThat's how I got to 0 from -11(P.S. upvoted)https://codeforces.com/blog/entry/155785?#comment-1383919https://codeforces.com/blog/entry/155785?#comment-1383919Sat, 08 Aug 2026 04:33:09 GMTis this your another id because yoor first solved question in this id is 1900 https://codeforces.com/blog/entry/155785?#comment-1383914https://codeforces.com/blog/entry/155785?#comment-1383914Sat, 08 Aug 2026 04:09:44 GMTI'm traumatized. Should I click or not?https://codeforces.com/blog/entry/155770?#comment-1383913https://codeforces.com/blog/entry/155770?#comment-1383913Sat, 08 Aug 2026 03:55:01 GMTThe people putting in the "effort"(I promise this is not a rickroll this time)https://codeforces.com/blog/entry/155770?#comment-1383912https://codeforces.com/blog/entry/155770?#comment-1383912Sat, 08 Aug 2026 03:49:22 GMTIt is not ratism, it is ragebait. Anyway, this is the most arrogant thing I have read in a while. Do you see how he sets the threshold based on his rating :D Why not ban everyone below 2400 or 2300 before gpt o3, including him? https://codeforces.com/blog/entry/155770?#comment-1383911https://codeforces.com/blog/entry/155770?#comment-1383911Sat, 08 Aug 2026 03:35:25 GMTIOI Community Discord Server | 2026https://codeforces.com/blog/entry/153660https://codeforces.com/blog/entry/153660Sat, 08 Aug 2026 02:44:03 GMTWhy I'm still -9 contrib?https://codeforces.com/blog/entry/155785https://codeforces.com/blog/entry/155785Sat, 08 Aug 2026 02:39:55 GMTyooo physics post!!!Just cuz its fun, here's where the definition of temperature is motivated from (this is called this microcanonical ensemble):Say you have two systems, the first has energy $$$E_1$$$ and $$$\Omega_1(E_1)$$$ microstates, and the second has energy $$$E_2$$$ and $$$\Omega_2(E_2)$$$ microstates. Then by conservation of energy $$$E_1 + E_2 = E$$$ is constant and once the two systems reach thermal equilibrium, the number of states of the combined system $$$\Omega_1 \Omega_2$$$ is maximized. Then, by differentiating the two expressions we can write $$$dE_1 = -dE_2$$$ $$$\frac{d}{dE_1} \left(\Omega_1 \Omega_2\right) = 0$$$ $$$\frac{d\Omega_1}{dE_1}\Omega_2 + \Omega_1 \frac{d\Omega_2}{dE_2}\frac{dE_2}{dE_1} = 0$$$ $$$\frac{d\Omega_1}{dE_1}\Omega_2 = \frac{d\Omega_2}{dE_2} \Omega_1$$$ $$$ \frac{d\Omega_1}{dE_1} \frac{1}{\Omega_1} = \frac{d\Omega_2}{dE_2} \frac{1}{\Omega_2}$$$ $$$ \frac{d}{dE_1} \ln\Omega_1 = \frac{d}{dE_2} \ln\Omega_2$$$$ So if we define $$$S = k_B \ln\Omega$$$ and $$$\frac{1}{T} = \frac{dS}{dE}$$$, then the temperature of two systems will be equal in thermodynamic equilibriumhttps://codeforces.com/blog/entry/155706?#comment-1383901https://codeforces.com/blog/entry/155706?#comment-1383901Sat, 08 Aug 2026 02:27:53 GMTHard C, Easy DE...https://codeforces.com/blog/entry/155718?#comment-1383899https://codeforces.com/blog/entry/155718?#comment-1383899Sat, 08 Aug 2026 02:10:28 GMTThanks for the interesting post, which provoked some thoughts...Normally entropy is defined with the Boltzmann constant, e.g. the Boltzmann entropy definition $$$S=k_B ln W$$$, so it does carry a physical dimension with the SI unit J/K. Thus $$$k_B$$$ appears in your temperature definition also. Byte is physically dimensionless, because logarithm can never carry a dimension (there is a nice proof, but this space is too small).Boltzmann initially hypothesized that $$$S\propto ln P$$$, and the constant of proportionality became $$$k_B$$$. Since $$$W\propto P$$$, the hypothesis evolved into $$$S=k_B ln W$$$. This has the added bonus of setting $$$S=0$$$ at zero temperature when any system would settle into a ground state with $$$W=1$$$. People argue about ground state degenercy, but that should be impossible in practice at zero temperature. Then again, zero temperture is itself impossible in practice.Entropy of a system is also related to the average information obtained by observing the system, with information defined as $$$I=ln P$$$, leading to the Gibbs entropy definition $$$S=-k_B \sum_i P_i ln P_i$$$. No one truly understands entropy.https://codeforces.com/blog/entry/155706?#comment-1383893https://codeforces.com/blog/entry/155706?#comment-1383893Sat, 08 Aug 2026 01:56:26 GMTCognition @ IOI 2026https://codeforces.com/blog/entry/155784https://codeforces.com/blog/entry/155784Sat, 08 Aug 2026 01:42:57 GMTDisagree. The number of cheaters is only kept within a range you're comfortable with because people are putting in the effort. Once people let up even a little, cheaters will spring up like mushrooms after rain.https://codeforces.com/blog/entry/155770?#comment-1383881https://codeforces.com/blog/entry/155770?#comment-1383881Sat, 08 Aug 2026 00:58:01 GMTI would like to inform you that, DuyMinh3005 6.5 is now better in detecting rickroll writting this with rickroll song playing in the backgroundbtw, I can't understand a word T-Thttps://codeforces.com/blog/entry/155706?#comment-1383878https://codeforces.com/blog/entry/155706?#comment-1383878Sat, 08 Aug 2026 00:28:14 GMTAnother day another GMeric W. I'm going to be taking AP chem this school year and im so fried lmao I can barely understand this :sob: like all I know is entropy is the second law of something and the first law of that thing has to do with conservation of somethinghttps://codeforces.com/blog/entry/155706?#comment-1383876https://codeforces.com/blog/entry/155706?#comment-1383876Sat, 08 Aug 2026 00:12:59 GMTExpert + thoughtshttps://codeforces.com/blog/entry/155717https://codeforces.com/blog/entry/155717Sat, 08 Aug 2026 00:11:05 GMTUseless Physics Information #9: How Does Thermodynamic Entropy Work?https://codeforces.com/blog/entry/155706https://codeforces.com/blog/entry/155706Fri, 07 Aug 2026 23:48:56 GMTIronic, why do you care so much about cheaters when you yourself admitted to your account using AI in contests, hmmmmm....https://codeforces.com/blog/entry/155781?#comment-1383871https://codeforces.com/blog/entry/155781?#comment-1383871Fri, 07 Aug 2026 23:31:02 GMTI found the obvious cheater: milky0002 [Evidence and proof] UDP: Cheaters in edu193https://codeforces.com/blog/entry/155781https://codeforces.com/blog/entry/155781Fri, 07 Aug 2026 23:27:04 GMTbro 2 mins ago (CM), bro now: Master!https://codeforces.com/blog/entry/155781?#comment-1383869https://codeforces.com/blog/entry/155781?#comment-1383869Fri, 07 Aug 2026 23:26:29 GMTSparse segment tree 2dhttps://codeforces.com/blog/entry/155750https://codeforces.com/blog/entry/155750Fri, 07 Aug 2026 22:10:54 GMTW Mikehttps://codeforces.com/blog/entry/155778?#comment-1383856https://codeforces.com/blog/entry/155778?#comment-1383856Fri, 07 Aug 2026 21:34:41 GMTThank you for reaching out. I can confirm the issue with invocations, and I am already working on fixing it. Sorry for the inconvenience!https://codeforces.com/blog/entry/155778?#comment-1383855https://codeforces.com/blog/entry/155778?#comment-1383855Fri, 07 Aug 2026 21:32:23 GMTPolygon Server Issueshttps://codeforces.com/blog/entry/155778https://codeforces.com/blog/entry/155778Fri, 07 Aug 2026 21:24:35 GMTDiv1/2 — generally, close to zero successful hacks, so system tests takes no time as all solutions have been judged on pretests alreadyDiv3/4 — let's eyeball and say maybe something like 50 based on https://codeforces.com/contest/2254/hacks?verdictName=CHALLENGE_SUCCESSFUL&chosenProblemIndex=, multiply by 15,000 participants who submit maybe 2-3 solutions on average, that's something like 30,000-40,000 tests to judge. If each takes about 0.25-1s, that's something between 2 and 11 CPU-hours spread out across all of CF's systems.https://codeforces.com/blog/entry/155777?#comment-1383835https://codeforces.com/blog/entry/155777?#comment-1383835Fri, 07 Aug 2026 19:40:43 GMT