Hello Codeforces!

We’re excited to welcome you to the upcoming DeepInfra Round 1 🚀

At DeepInfra, we’re building high-performance AI infrastructure that makes running the world’s best AI models fast, reliable, and accessible. We operate across the entire inference stack — from GPUs all the way to the API — and we care deeply about performance, efficiency, and solving hard engineering problems.

Our team had great experience with being part of Codeforces and competitive programming community — PERNEKHAN, yessenzhar, Zharaskhan, Johan.de.Ruiter, rmn and many others. One of them even participated in Codeforces Beta Round 50 (so we're kinda OG here xD). That’s why we’re excited to be hosting this contest. We love meeting people who enjoy tackling challenging problems, thinking creatively, and pushing themselves technically.

We’re growing, too! DeepInfra is headquartered in Palo Alto, California, with an office in Sofia, Bulgaria, and we’re hiring software engineers and interns. If you enjoy this kind of problem solving and want to work on challenging systems at the intersection of AI and infrastructure, we’d love to hear from you.

To apply for Software Engineering interns and full-time positions, fill in the application form and we will be in touch.

Learn more about us and what we’re building on our website.

Join us on Oct/10/2026 18:05 (Moscow time) to win great prizes:

• Top 3: 1000 USDT + merch
• 4-6: 250 USDT + merch
• 7-10: 150 USDT + merch
• Random 10 from the top 100 (excluding top 10): merch

Good luck to everyone competing — have fun, and we’ll see you on the leaderboard! 🏆

— The DeepInfra Team

Official quote

ICPC Foundation and Quora are pleased to invite you to an ICPC Alumni Meet-Up in Silicon Valley on Wednesday, July 2, 2025 from 5:30pm — 9:00pm. We will gather at Quora HQ located at 605 Castro St, Mountain View, CA 94041. Venue capacity is limited, so registration is subject to approval by ICPC.

The 2025 ICPC World Finals Baku hosted by ADA University will be held on August 31 — September 5, 2025. Visit icpc.global for more information. Guest speakers will introduce ICPC World Finals: * Fuad Hajiyev, Contest Director — The 2025 ICPC World Finals Baku * Sadig Akhundov, IT Director of CBAR — Impact of ICPC to the financial sector * Shahin Aliyev, Deputy Chairman of IDDA — Digital Azerbaijan

Register by the link

Personal quote

To those who are in the Bay Area, lets gather on the meetup. Some legends will be there, last year was fun:)

P.S: me with ACube, and Seyaua x sdya

UPD: The calculation updated, for some reason I filtered only CF style competitions. Now it includes everything. Still ruban best :)

I revisited some data from Codeforces and, after 5 years, decided to calculate again who has participated in the most contests. I took into account all official contest participations, including those where a user participated unofficially. However, I excluded Practice/Virtual contests.

P.S: I think no one will beat ruban ever :)

Rank	Handle	Total	Official	Unofficial
1	ruban	1164	1090	74
2	kmjp	972	547	425
3	dreamoon_love_AA	891	538	353
4	coderbd	867	789	78
5	kzyKT	863	626	237
6	PAG	834	814	20
7	balakrishnan	807	656	151
8	natsugiri	776	544	232
9	uwi	766	467	299
10	_LeMur_	686	552	134
11	Jimanbanashi	640	469	171
12	Gassa	622	463	159
13	eugalt	619	618	1
14	xish	618	573	45
15	Hasan0540	610	425	185
16	leaf1415	606	359	247
17	titia	596	362	234
18	KrK	588	381	207
19	Mukundan314	581	512	69
20	SmartCoder	574	561	13
21	_Dragon_	571	504	67
22	sutekine	566	551	15
23	Golovanov399	556	440	116
24	oversolver	551	367	184
25	Farhod	551	393	158
26	STommydx	548	393	155
27	hank55663	540	369	171
28	Hyperbolic	535	314	221
29	Wandoka	523	410	113
30	I_am_Heisenberg	518	505	13
31	emthrm	515	293	222
32	rainboy	511	372	139
33	dush1729	505	460	45
34	nuip	503	385	118
35	AntiBsayer	500	348	152
36	Um_nik	494	373	121
37	Subhashis_CSE	490	487	3
38	ScarletS	488	415	73
39	Egor	487	363	124
40	Dukkha	485	441	44
41	Zain	482	475	7
42	chemthan	470	324	146
43	akshay_1	469	412	57
44	vladmart	468	335	133
45	Mujahid	468	442	26
46	antguz	465	381	84
47	Kawaii	463	433	30
48	risujiroh	459	305	154
49	naeem4265	459	427	32
50	HopefulSpecialist	454	453	1
51	Ruban_Denic	453	452	1
52	mban259	452	302	150
53	cjoa	450	390	60
54	espr1t	449	410	39
55	kotatsugame	448	251	197
56	1435730	447	438	9
57	TripleM5da	445	310	135
58	KKT_89	443	329	114
59	irmuun	442	329	113
60	BigBag	440	333	107
61	jiangly	439	259	180
62	Nero	439	305	134
63	Go8	439	403	36
64	mjnbcfbot	436	357	79
65	nhho	432	333	99
66	iMurat	429	425	4
67	ei133333	428	277	151
68	_c_k_r_	428	393	35
69	_Subrata	428	390	38
70	SajidZakaria	428	374	54
71	vangtrangtan	427	372	55
72	rsFalse	427	419	8
73	cuiaoxiang	427	205	222
74	Marckess	425	257	168
75	tnaito	424	344	80
76	I_love_Tanya_Romanova	423	301	122
77	tute7627	422	254	168
78	kaiboy	422	410	12
79	Bedoo	419	369	50
80	Nafis.Shahriar	415	385	30
81	ksun48	411	338	73
82	bi11a1	409	379	30
83	rkb_rd	408	398	10
84	codelegend	408	307	101
85	shahidul_brur	405	391	14
86	physics0523	405	280	125
87	Ferume	405	383	22
88	kiyotaka	405	354	51
89	Azat_Yusupov	405	310	95
90	curly_braces	404	346	58
91	shahed_ahmed	402	370	32
92	IceKnight1093	402	281	121
93	darkkcyan	401	301	100
94	Kude	401	211	190
95	Andreasyan	401	282	119
96	tourist	399	348	51
97	Lawali	399	295	104
98	awoo	398	331	67
99	Uzumaki_Narutoo	398	369	29
100	tuananh238	396	353	43

We invite you to first ICPC alumni event in Silicon Valley on June 4 at 6pm.

This is a unique event that will bring together top ICPC alumni and friends. The event will be attended by ICPC President Bill Poucher, Freedom Holding CEO Timur Turlov and Bagdat Mussin, President of the Kazakh Federation of Competitive Programming.

Register here: https://lu.ma/ICPC_Meetup

P.S: wdyt about some small entertainy contest?

Hello codeforces,

link is coming, the event with Bill Poucher and Kazakhstan Team. They have some limited space, and the only requirement is being related to the ICPC community.

P.S: Just wondering is there any ICPC related clubs in Bay Area?

Any plans to host this contest mirror? Yandex or Codeforces?

So far I thought that the number of lost points per minute is calculated by formula initial_cost / 250. According to this post I'm correct. But after some lookup into standings of last contest I found some contradictions:

• Problem А (500 points): 1 point per minute
• Problem B (750 points): 2 points per minute
• Problem С (1000 points): ~2.67 points per minute
• Problem D (1500 points): 4 points per minute
• Problem E (2000 points): ~5.33 points per minute
• Problem F (2500 points): ~6.67 points per minute
• Problem G (3000 points): 8 points per minute
• Problem H (3500 points): 9.33 points per minute
• Problem I (4000 points): 10.67 points per minute

That definitely says that I was wrong. I'm not complaining about format or something else. Just want some explanation of exact formulas. Am I missed some new clarification on that thing MikeMirzayanov?

P.S: just seeking for explanation after no answer on comment. Constants was calculated from great performances of boboniu and maroonrk.

This is top users with most participated in official contests of 2019, included non-rated ones.

This is top100 with most participated in official contests, included non-rated ones.

Rank	Handle	Total	Official	Unofficial
1	ruban	660	612	48
2	PAG	604	585	19
3	uwi	587	352	235
4	dreamoon_love_AA	511	351	160
5	kmjp	506	319	187
6	KrK	471	314	157
7	Hasan0540	458	311	147
8	natsugiri	453	319	134
9	coderbd	431	408	23
10	_LeMur_	422	354	68
11	Jimanbanashi	415	293	122
12	Azat_Yusupov	405	310	95
13	guille	392	255	137
14	hogeover30	384	337	47
15	balakrishnan	383	327	56
16	kzyKT	375	296	79
17	I_love_Tanya_Romanova	371	276	95
18	sutekine	362	352	10
19	Gassa	359	291	68
20	Farhod	354	256	98
21	MrDindows	353	275	78
22	SlavaSSU	343	278	65
23	shahidul_brur	340	329	11
24	shakil_AUST	331	322	9
25	zhabo	329	299	30
26	nhho	329	239	90
27	torus711	317	280	37
28	DatoTS	314	309	5
29	Egor	313	249	64
30	rsFalse	312	304	8
31	Sonechko	312	258	54
32	daiota	307	304	3
33	oversolver	307	215	92
34	kiyotaka	304	264	40
35	fauzdar65	303	275	28
36	I_love_tigersugar	300	210	90
37	mystery_boy	300	285	15
38	Temirulan	300	231	69
39	MishaPrigara	298	275	23
40	BigBag	298	221	77
41	Um_nik	297	234	63
42	goodhope	296	286	10
43	1100011101	295	246	49
44	eddy1021	294	203	91
45	chemthan	294	199	95
46	_Dragon_	294	254	40
47	Shavkat_Aminov	293	243	50
48	yermak0v	292	253	39
49	--Pavel--	292	226	66
50	okuzn	292	285	7
51	gskhirtladze	292	234	58
52	RedNextCentury	292	226	66
53	_HossamYehia_	290	281	9
54	nuip	289	226	63
55	buggy.code	284	270	14
56	alexyz	284	227	57
57	tantam75	283	269	14
58	espr1t	283	247	36
59	ngfam_kongu	282	202	80
60	quandum	280	270	10
61	Taube	280	229	51
62	mmaxio	279	239	40
63	ei133333	278	188	90
64	Golovanov399	278	256	22
65	vanogam	277	249	28
66	abisheka	277	237	40
67	Svyat	276	222	54
68	shahed_ahmed	272	251	21
69	flashmt	272	209	63
70	Wild_Hamster	272	218	54
71	Alhelal_01	272	265	7
72	allllekssssa	271	221	50
73	Elibay	270	262	8
74	abistrigova	269	212	57
75	AntiBsayer	268	209	59
76	chrome	267	259	8
77	sahedsohel	266	218	48
78	Tima	266	202	64
79	I_am_Heisenberg	265	261	4
80	emotionles	264	260	4
81	adamant	264	245	19
82	Decayed	262	261	1
83	bhadra	261	220	41
84	mexmans	261	192	69
85	dush1729	260	256	4
86	alex_bucevschi	260	255	5
87	Oryshych	260	176	84
88	bohuss	258	240	19
89	Sokolov	258	215	43
90	Rubanenko	258	187	71
91	Ferume	258	251	7
92	P___	257	230	27
93	ABalobanov	257	173	84
94	rotavirus	256	226	30
95	gamezovladislav	256	248	8
96	__math	256	174	82
97	Hiasat	256	215	41
98	specia1	255	186	69
99	naagi	254	202	52
100	KADR	254	243	11

Given two weighted trees. f(x, y) — distance between x and y in the first tree, g(x, y) — distance between x and y in the second tree. How many pairs (x, y) such that x < y and f(x, y) < g(x, y). Number of vertices <= 2*10^5.

UPD: go here

There some strange things happen with problems on Topcoder. Problem statement page is empty, but it can be seen in arena applet. And this happens for many problems. Some examples: link link link link. Is this known issue?

Hi everyone!

4 Europe Regional contests out of 5 was already passed. Depending official information 15 teams from Europe already passed to World Final. Congratulation!!!

I added one of them to Gym. On official website there is only test data and jury solutions. Unfortunately, there is no checkers. Feel free to fix bugs :)

Time constraints was assigned depending on execution time of jury solutions. On official contest there was very high time limits, maybe because of Kattis servers.

Added contest to the Gym. On website I found only tests. And checkers was prepared on my own, feel free to fix. Does anybody have jury solutions?

Let's discuss problems.

How to solve E and F.