Блог пользователя Z0RR0

Автор Z0RR0, история, 4 года назад, По-английски

I have been with codeforces for a long long time. It has been always my thought that why codeforces rounds are only 2 hours (usually). The things that I am sharing right now are just my opinions.

I think a CF contest's difficulty is chosen by looking at the very topmost population. Maybe like 5% of the population. They should complete or almost complete the problemset within the contest time. Well, that's fair I guess. But from the top, 50% or even maybe from the top 25% would feel that they could solve another one if there was more time. That's true for everyone else too I guess.

Let's say a usual codeforces round is now 3 hours. What are the pros? Most of the contestants will get 1 extra hour to think with 1 or 2 more problems that they don't get to solve within 2 hours. Speedforces effect should be reduced at least a bit. A slow but knowledgeable contestant might end up higher on some fast contestant who used to be on top of him most of the time. Doesn't everyone want to be separated by problem solve count rather than the speed! And 2 hours of the contest does not let you much time to recover. 3 hours of contest would let you much time to recover and could enforce different strategies. Some problem requiring 90-100 minutes to solve for a certain person is almost impossible to solve within the 2 hours contest time.

What are the cons? The topmost guys would finish the contest very early. But it also happens in 2 hours contest too. Some guys finish X problems and they still had 30-40 minutes which is very low to solve the next one. Another problem is they have to sit through the whole contest because of hacks may be. Some people might be unable to find 3 straight hours of free slot. And is it a problem that 3 hours of contest would put heavy pressure on the server (maybe in terms of cost too)? I don't think this one is an issue though. One problem could be someone might find it better with 4 hours rather than 3 hours, some might find it better with 5 hours of the individual contest. It's a never-ending debate about what is suitable.

There could be many other pros and cons. But my point is maybe 2 hours is too low for a contest. I think most of the contestants put an extra hour at least on the almost solved one/thinking for a long time one on the pen-paper or in the comment section may be. Putting that hour in the contest itself might be more interesting.

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Автор Z0RR0, история, 6 лет назад, По-английски

Hello Codeforces!

There has been several blogs similar to this. I know about TOP 15 most popular users on codeforces and Who is the most popular?. But as none of these are updated, I thought this might be helpful.

I have just calculated the most popular handles in Codeforces. I only considered those handles which have at least one rated contest. Begging my pardon to them who hasn't participated in any rated round. And here, the popularity depends simply on the number of people you are friend of.

The complete standings can be found here(This may took a while to load at the bottom).

Anyway here is Top 200 handles.

Rank Handle Follower
1. tourist 14082
2. Petr 6430
3. jqdai0815 4202
4. rajat1603 3074
5. rng_58 2941
6. I_love_Tanya_Romanova 2405
7. YuukaKazami 2145
8. Um_nik 2123
9. ahmed_aly 1973
10. dreamoon_love_AA 1875
11. nfssdq 1824
12. Egor 1627
13. Sumeet.Varma 1592
14. quailty 1522
15. Endagorion 1495
16. dragoon 1470
17. uwi 1446
18. akashdeep 1437
19. PrinceOfPersia 1409
20. matthew99 1402
21. ACRush 1382
22. Baba 1327
23. jcvb 1324
24. Errichto 1314
25. dotorya 1275
26. anta 1223
27. Radewoosh 1219
28. kingofnumbers 1214
29. Zlobober 1198
30. scott_wu 1188
31. MinakoKojima 1186
32. gvaibhav21 1180
33. subscriber 1177
34. zscoder 1166
35. RetiredAmrMahmoud 1146
36. jtnydv25 1130
37. V--o_o--V 1107
38. darkshadows 1092
39. satyaki3794 1086
40. Syloviaely 1073
41. anudeep2011 1069
42. niyaznigmatul 1064
43. akulsareen 1050
44. Jami_CSEDU 1040
45. adurysk 1029
46. ftiasch 1016
47. Ahmad_Elsagheer 1013
47. LHiC 1013
49. Swistakk 988
50. KhaledKEE 971
51. I_love_Hoang_Yen 969
52. yeputons 946
53. Reyna 904
54. TsunamiNoLetGo 895
55. Hasan0540 884
56. Haghani 879
57. Alpha_Q 866
58. adamant 862
59. fateice 851
60. Z0RR0 845
61. karanaggarwal 844
62. zetamoo 843
63. sahedsohel 841
64. Corei13 833
65. teja349 829
65. triploblastic 829
67. raihatneloy 827
68. ainta 825
69. JoeyWheeler 820
70. netman 818
71. 300iq 810
72. xorfire 808
73. bertho_coder 807
74. TooDumbToWin 803
75. khatribiru 799
76. Balajiganapathi 795
76. Shafaet 795
76. alecsyde 795
79. W4yneb0t 787
80. sn23581 783
81. vepifanov 780
82. mrtempo 778
83. forthright48 777
84. watashi 769
85. PraveenDhinwa 764
86. ruhan.habib39 760
87. Labib666 758
87. NourElRashidy 758
89. Bruteforceman 746
89. halyavin 746
91. Xellos 745
92. KAN 738
93. Shahriar_sust 737
94. fsshakkhor 736
95. sevenkplus 735
96. Claris 731
97. PavelKunyavskiy 722
98. TankEngineer 716
99. GlebsHP 710
100. FizzyDavid 705
101. cgy4ever 704
102. Mohammad_Yasser 700
102. andrewzta 700
104. bhadra 697
105. noor148 689
106. bmerry 685
107. sd0061 676
108. -XraY- 671
109. Burunduk1 670
109. Honour_00 670
111. I_love_tigersugar 667
112. fegla 657
112. qwerty787788 657
112. worse 657
115. Arpa 653
116. Yousef_Salama 652
117. ko_osaga 644
118. Pepe.Chess 640
118. adkroxx 640
120. Ashishgup 631
120. Smit 631
122. MohamedZain 630
123. Benq 628
123. Deemo 628
123. Egor.Lifar 628
126. Tanzir5 608
127. a0666 607
128. chemthan 601
129. matrix 600
130. riad 591
131. rachitiitr 590
132. J-C 589
133. ndatta 588
134. OmarHashim 584
134. VastoLorde95 584
136. Rubanenko 583
136. mahbubcseju 583
138. yutaka1999 582
139. jiry_2 579
140. LiTi 576
141. Matrix.code 572
141. rubabredwan 572
143. Darooha 570
144. comfi 569
145. peter50216 565
146. eatmore 564
147. Monmoy 562
148. architkarandikar 560
148. mathlover 560
150. ffao 558
150. m.radwan 558
152. Bidhan 554
153. harrypotter192 552
154. hyoussef 546
155. Na2a 544
156. Silent_coder 543
156. chrome 543
156. hitman623 543
156. shakil_AUST 543
160. himanshujaju 541
161. kuangbin 540
162. hasib 539
163. HYPERHYPERHYPERCUBELOVER 535
163. eddy1021 535
163. moinul.shaon 535
166. LinKin 534
166. tweety 534
168. I_See_You 532
168. SameerGulati 532
170. TripleM5da 529
171. KrK 528
172. MrDindows 524
172. Sereja 524
174. jAckAL_1586 522
174. usaxena95 522
176. triveni 518
177. Temirulan 517
178. Noureldin 516
179. rumman_sust 515
180. .o. 513
181. Rezwan.Arefin01 512
182. jehad131 510
183. pulkitg10 506
184. mostafa.saad.fci 505
185. M.Mahdi 501
186. codename27 500
187. BitHashTech 499
187. havaliza 499
189. imAnik 498
190. Nada 494
190. flash_7 494
192. Hiasat 492
193. mk_Shahriar 491
194. pranet 490
195. Arg_007 489
196. demon1999 488
197. BishalG 487
198. FlaminRage 485
198. Shik 485
198. aka.Sohieb 485

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Автор Z0RR0, история, 6 лет назад, По-английски

I tried to learn how generating functions work using wikipedia and some youtube videos but could not get much idea about that. I can generate some simple recurrence relations using generating functions.

Can anyone provide me or share some other resources to learn more?

And it would be really helpful if you can share some problems regarding generating functions. Any tips and tricks would be also helpful.

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Автор Z0RR0, история, 7 лет назад, По-английски

Is it possible to find MinCost MaxFlow if there is a negative cycle on the network?

For clarification: in this given network, each edge has unit capacity and the number denoted on each edge defines the cost. A is source and D is sink. In this network MaxFlow is 1 and MinCost is -3.

How to calculate the MinCost properly?

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Автор Z0RR0, история, 7 лет назад, По-английски

Can someone provide a few problems solvable with Lagrange Multiplier ? I have solved just one problem UVa 12407 and want to try some more.

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Автор Z0RR0, история, 8 лет назад, По-английски

is there any O(n) or O(nlogn) solution to find minimum number of partition of a string where each partition is a palindrome ? there is simple O(n^2) dp solution for this. but is there any greedy insight or any better solution to make it better than the normal dp solution ?

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Автор Z0RR0, история, 9 лет назад, По-английски

This might not be a real matter of concern but specially in Div1 contests a lot of contestants do not submit anything if they are not able to solve any problem. Last round(round #317) their was an opportunity to get t-shirts and top 200 is quite achievable if it is a lucky day for you. So,normally you would expect a lot of contestants in that contest. But their was less than 700 participants. The round was really a tough round and I think more than 300 people were there who tried but could not solve any,thus they do not submit any. It is quite disappointing for them who solved some and would get better rating if they all attended as they went zero solve in that contest.

Again,In some contests participants usually try for B rather than A because solving only A would not boost his rating.And when they can not solve B then they do not submit any. This is looking quite disappointing to me. So, I am asking if it is possible to make any system that one has to make sure that he is rated for this contest either he submits any or not and it is at the very beginning of the contest ? If you do not make sure at the very beginning then you are not rated for the contest. People can not even cheat with another account because they have to make sure at the beginning of the contest if they are attending or not. In few initial minutes they will not be able to decide if they can manage to solve that task they decide. So actually one has to be predetermined if he is really attending the contest or not.

If someone can not manage to prepare any solution to submit for any problem why would he want to make lower his ratings (Although I saw one of my friend got WA on testcase1,problem A because he tried the whole contest and can not generate any solution and he wrote that he did not deserve to be in div1) ! But the fact is he deserves the lower rating and one who solves deserves higher rating as there would be more participants. So,is it possible to do something to make sure that one is participating ?

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