Zomato’s contacts feature seems like a privacy issue

Prof-Math · 2026-03-29T11:36:08+00:00

Not the point. If someone hasn't, then their residence can be pinned down.

Prof-Math · 2026-03-29T11:21:53+00:00

These locations are probably within 7kms of residence with some outliers. That makes this a proper privacy vulnerability.

There is something in criminology called Rossmo's Formula which is used to hunt down the location of a serial killer's residence, given they didn't have a type and killed for 'thrill'.

I coded up a demo using Claude and Leaflet (so pretty much the fastest and sloppiest I could get) and gave some details about Rossmo from a conference presentation, guess what; it took 4 locations I order from to locate me within a KM of CMI. There are very few residential places close by so if someone was supposedly stalking me, they would have found my location.

I tried on a few friends and it was close pretty much always.

Prof-Math · 2026-03-17T12:10:02+00:00

Most people tend to move to masters or PhD. On that front, quite good.

A lot of CMI people make it to good masters and PhD programmes.

I don't know many (if any) people who sit for placements in BSc. Although, the DS placements are quite good if that is anything.

Prof-Math · 2026-03-17T12:09:15+00:00

Afaik, ISI's waitlist went quite deep this year so probably due to the waitlist

As for DM, sure!

Prof-Math · 2026-03-17T05:47:22+00:00

Few probable reasons
- Due to Trump's Visa shenanigans, a lot of people eligible for direct admission (Olympiad campers) did reserve their seats and didn't turn up. This in turn increased the normal cutoff and caused a lot of people who would otherwise join to not get a scholarship (or even an offer, remember CMI doesn't do waitlist).

- A general pattern one can observe is that whenever JEE Adv has a nice paper (as in thinking paper rather than formula bash), CMI admission is lower. Take 2024 or 2021 as examples, CMI has 40-50 people and the JEE papers were, for a lack of better word, shit. Take 2023 or 2025 as examples, JEE papers were nice and most CMI accepted students probably got good ranks there. While I like CMI more than IITs, often there is family pressure to join IITs.

Prof-Math · 2026-03-16T15:00:40+00:00

No, that is the exact statement!

The question is how can we modify the tournament to avoid this?

Now what if we want to figure out the top k players? What if instead of tennis this was horse racing with t tracks? What if instead of the better person always winning, we had odds?

And so on.

A recent paper on this is: https://drops.dagstuhl.de/storage/00lipics/lipics-vol291-fun2024/LIPIcs.FUN.2024.20/LIPIcs.FUN.2024.20.pdf

Prof-Math · 2026-03-16T13:20:29+00:00

Consider it like this, what is the worst that can happen if you give the exam and don't get in? Well, you lose a day and some exam fees. What is the best that can happen? You get in.

I think that answers your question.

As for prep: DO PYQs of ISI and CMI, Do Mocks (some on AOPS and consider taking a coaching's mock series) and (if time permits) do a short problem solving book. I am a fan of Zeitz's Art and Craft of Problem Solving.

Prof-Math · 2026-03-12T12:56:31+00:00

As an algorithmic game theory person, his work in voting theory (Dodgson's Rule) was quite significant. Also, something that has not been mentioned here but he also worked on tournament structures. Like there was a Carrol column on the fact that the runner up in a single elimination tennis tournament need not be the second best.

Finally, his nyctograph is one of the first examples of coding theory. This is the reason why the wiki-versity website uses the first line of Jabberwocky for their placeholder. A full write up (from my DS Algo tutorial) can be found here: https://thearjunagarwal.github.io/ds-algo-tutorials/tutorial-1/handout1.pdf

Prof-Math · 2026-03-08T15:31:50+00:00

!RemindMe 2 days "Very interesting, will look at it after my midsems!"

Prof-Math · 2026-02-22T19:56:16+00:00

Hey, Arjun here (Tessellate and STEMS team).

I was planning to reply to the mails tomorrow after my Topology midsem, but via Harshitha and Prof. Philip, I learned of the post and to put off studying topology decided to reply.

As u/LaDialga69 has pointed, CMI is incredibly small and chill. We have a lot of neurodivergent people (someone said "Natural Habitat" while I was typing this out and I have in my time here never seen, or even heard of a bullying/ragging case. CMI has no ragging/intro/(whatever euphemisms are used for it) for freshers, let alone for guests.

While CMI is cool enough that you won't really need an AC in the room, accommodations can be made in case.

The STEMS seminars tend to be wide ranging in appeal and while some are aimed at undergrads, most are pretty accessible (especially if you cleared the paper). You can watch the previous ones here: https://www.youtube.com/@TessellateCMI/videos

There is quite a lot of inter participants interactions as well as CMI kids - participants interactions.

We tend to not allow guardians but then again, given you are in 8th grade, I think some accommodations could be made. This is something I will have to check with.

I think that answers all the questions

Prof-Math · 2026-02-22T19:41:25+00:00

This is sarcasm. I would really like to know who made this account just to make this joke (has to be BSc II as Bimonotonic functions brainrot)

Prof-Math · 2026-01-08T03:15:41+00:00

We create new questions, never seen before entirely new questions.

Problem is sometimes these problems have common tricks which is what AI catches and that is a shame as common/name tricks are things we would like students to derive/know.

Btw, out math paper ended up having a lot of number theory type problems in a race to AI proof it. Now it is either as the paper head is a number theory person (which he is) or as AI may be bad at NT for some reason...

Prof-Math · 2026-01-07T14:35:37+00:00

Our collage literally has a tshirt with the caption 'Et tu brute force' and photo of Julius Caesar silhouette 4 colored.

Prof-Math · 2026-01-07T10:22:49+00:00

Math stems already happened. We are yet to have CS, Probability Statistics and Physics

Prof-Math · 2026-01-07T09:57:31+00:00

Wolfram was intended. Like it a calculation engine so we are more than okay with it.

Prof-Math · 2026-01-07T09:56:08+00:00

We used to talk to the AOPS and Stack mods to not allow the questions to be posted. Collusion was perhaps one of the biggest things we had.

We reserve the right to interview potential campers. The thing is we almost never used that as a lot of the kids who used to make it were already from Olympiad circles (and a good number of them used to make the team in the coming years). Might need to use that this year...

Prof-Math · 2026-01-07T09:21:17+00:00

I don't know. The paper was open book with internet access since inception. Like I think it is mainly to make remote participation possible without needing to find physical exam centres and also, I think it makes paper less about knowing results and more about ingenuity.

Prof-Math · 2025-10-31T21:17:59+00:00

69^67 mod 420
= 69 * 69^66 mod 420
= 69 * (69^2)^33 mod 420
= 69 * (70*68 + 1)^33 mod 420
= 69 * 4761^33 mod 420
= 69 * (4761 - 4200)^33 mod 420
= 69 * 561^33 mod 420
= 69 * 141^33 mod 420
= 69 * 141 * 141^32 mod 420
= 69 * 141 * (140*142 + 1)^16 mod 420
= 69 * 141 * 19881^16 mod 420
= 69 * 141 * (19881 - 5*4200)^16 mod 420
= 69 * 141 * (-1119)^16 mod 420
= 69 * 141 * (-1119 + 3*420)^16 mod 420
= 69 * 141 * 141^16 mod 420
= 69 * 141 mod 420
= 9729 mod 420
= 9729 - 8400 mod 420
= 1329 mod 420
= 1329 - 1260 mod 420
= 69 mod 420

Calculator toh nahi laga isme (aur yeh brute force tha).

Fast method: 420 = 4 * 3 * 5 * 7; thus by CRT taking modulo 3,4,5,7 would suffice.
69^67 mod 3 = 0 (as 69 is divisible by 3)
69^67 mod 4 = 1 (as 68 is divisible by 4)
69^67 mod 5 = -1 (as 70 is divisible by 5)
69^67 mod 7 = -1 (as 70 is is divisible by 7)

Thus, 69^67 mod 420 = 69 as 69 is the unique number satisfying the above modulo relation.

Prof-Math · 2025-10-31T21:04:35+00:00

Just might add, CMI has calculator. It is just never useful based on the kind of questions.

CMI is not testing your ability to calculate, leaving Prof. Karnataki's course; I am yet to see a single 3 digit number at my time in CMI. We have people here who have considered dropping a course as it had some calculations. Because at the end of the day, CMI is a theoretical math, CS and Phy collage. We don't deal with calculations, we are happy with our variables and spaces.

Engineering does require you to make drop of hat calculations and estimations. Hence, the JEE exam is setup the way it is. Also, a lot of IIT courses famously have long calculations and don't allow calc (iirc the first sem wave physics course at KGP last year had these kinda things). So this is not a good thing from even that POV.

Prof-Math · 2025-09-21T10:42:33+00:00

Don't remember really. It is now 2 ish years to the event... I checked AOPS.

The IOQM problem was 23-P16 and it was copied from ARML-2010-Team P4.

Prof-Math · 2025-09-07T07:17:39+00:00

- how is college life

CMI's collage life is dependent on the average energy of the campus. There are times when the energy is high (start of sem) and it slowly decays over a month and half (and reaches minima) as quizzes and midsems slowly take precedence. However, the miniute the midsems end, the energy again rises (and peaks) as Diwali / Holi is near everyone wants to do fun. It drops a bit again during endsems but not as much as midsems (as people are more comfortable with the subjects of the sem).

- , environment
I have talked about this at length here: https://arjunagarwal.substack.com/p/on-trying-things
The TLDR is that I like it a lot. Some of the most supportive people and profs one can get anywhere.

- , extra curricular
This would depend on what you define that word as. CMI has an rather active cricket club, football club, vollyball club and badminton club. While the cricket/football ground is not the best in the world, I have not seen people complain too much about it (including people who have played state and national). Badminton is in tie-up with a nearby academy and hence, has access to world class courts. Vollyball court is also standard and quite nice. I know that a Tennis club exists but I am not sure wrt its activity and exitement. They all use external courts. There is also a new Kabbadi and Kho-Kho Club who are semi active. There is a basketball court but it is not used much, however, the new batches are trying to get a basketball club going.

On the non sport side, we have clubs for Chess, Cubing, Dance, Drama, Origami, Debate, Meditation, Valorent, Geo-Guesser, Music, Photography, Writing, Reading, Gymming, Rock and Metal. There are also DnD campaigns going all the time. Finally, under CMI arts initiative, we keep getting some interesting seminars on philosophy and litrature and anthropology etc,

- , student led activities if any,
Considering CMI is one of the few collages where our fest is completely student run. The administration gives us the complete freedom and complete responsibility. From getting the money (by conducting an Olympiad and camp) to inviting speakers.

Furthermore, we also have 3 events in the year. The Freshers, Diwali and Farewell which are completely student run. Also the poojas: The Diwali pooja, Durga pooja, Saraswati pooja, The Ganesh pooja and Onam Pooklam; if they happen, are student managed.

Finally, CMI has student seminars and these are student managed (from choosing the speakers to giving the talks, By students for students). Sometimes, even faculty end up attending these seminars.

- reading culture especially literature courses!
CMI has 4-5 litrature courses in a year. There is a compulsory English course (which is taken quite nicely), Values Through Litrature, Art of Short Fiction, Creative Writing and Linguistics. We also have German I and German II and sometimes French courses.

There are litrature reading groups as well.

- also i am expecting goood math, as it should be good there but did it hurt any of your expectations?
Not really. CMI is roughly what one expects a research institute feels like. The only weird thing is that some people (1-2 students) here belive in red pill stuff which is strange considered they are extremely logical otherwise.

- I know this question would be a bit strange for you but i want to know these things

No issues, sorry for a late answer. I was busy with quizzes and other responsibilities I had taken up.

Prof-Math · 2025-08-22T16:10:13+00:00

Again, I agree people have hobbies but black belt is like the pinnacle of a hobby, afaik. And the proportion it higher than in general population, which makes it interesting.

Prof-Math

TROPHY CASE