Dear ICPC participants!
Welcome to the 2019 ICPC Caribbean National Contests. This is the very last step the teams have to take in order to qualify to the Regional Finals . The time has come to find out which are the best teams from each country .
We are glad to announce that there are 195 official teams from 42 institutions and 5 countries. Additionally, 2 company teams, 26 preuniversity teams and 24 guest teams will participate. That means in total 247 teams will try to solve the programming tasks proposed by the judges ! We wish you the best of luck, a lot of fun and many .
In case you are at some of the competition sites and took some pictures , it would be great if you could share them by sending an email to icpc@uci.cu .
Country  Teams  Institutions 
Cuba (
Results
)

161  25 
Dominican Republic (
Results
)

13

7

Puerto Rico (
Results
)

11  4 
Jamaica (
Results
)

5

2 
Trinidad and Tobago (
Results
)

5  4 
Totals:
5 countries

195

42

If your team did not qualify, it only means that you have to practice a bit more.... it's not because the problems were hard. Don't be disappointed . Unfortunately, not all teams can go to the next level . If you train enough , next year you will definitely make it !
These are the links to the warmup and real contest:
Warmup contest: 
https://matcomgrader.com/contest/overview/6247

Oct. 5, 2019, 10:30 a.m

Real contest: 
https://matcomgrader.com/contest/overview/6248

Oct. 5, 2019, 1:15 p.m

LIVE Comments of the competition
Here we will keep you posted with everything that happens during the contest!
[10:30]  The warmup contest has just started. This time it will be longer than usual because not all the teams in the Caribbean will be able to do it at the same time. In this contest, the teams should check that everything works properly and also get some practice before the real one.
[10:31]  The team Train a Lot from Universidad de Ciencias Informáticas (UCI) just solved the first problem A after only 1 minute . It seems that they have been training a lot!
[10:34]  3N1?M4 from Universidad Central "Marta Abreu" de las Villas (UCLV) solves problem B !
[10:36]  ◔ Pacmen ••• from Pontificia Universidad Católica Madre y Maestra solved problem C !
[11:15]  So far, 131 have solved at least one problem .
[11:25]  The warmup will continue until 1:00 pm (Cuban local time) . We already look forward to the real contest , which will start at 1:15 pm (Cuban local time).
[11:35]  The public actions , such as messages, posts or comments are currently blocked for security reasons. If you have any comments or you find any error please send us private feedback using the blue button on the bottomright corner (you need to be logged in to be able to see the button).
[13:00]  The warmup is over! In total 164 teams solved at least one problem. The real contest will start in a few minutes!
[13:15]  The 2019 ICPC Caribbean National Contests have just started, the best of luck to all the teams.
[13:20]  Read the problem statements in English and Spanish .
[13:23]  Teams UH++ and ◔ Pacmen ••• opened the scoreboard with a in problem J after 8 minutes from the start.
[13:24]  Limitless gets first to solve on problem H . Notice that this problem has two versions.
[13:30]  Limitless strikes again and is the first team with 2 solved problems H and J . This team is leading now!. Let's see if they really have no limits .
[13:50]  The team ◔ Pacmen ••• becomes the first one to solve the problem F .
[13:55]  So far, 10 teams have 2 problems solved and other 18 have 1 problem solved. Team Limitless is still leading in the unified standing (considering all teams from all countries in the same ranking).
[14:05]  Limitless is trying problem D but they got wrong answer .
[14:10]  ◔ Pacmen ••• has solved problem H and becomes the first team to get 3 solved problems J , F and H . They are leading now!
[14:15]  UH++ solved problem F and has now also 3 problems solved with 1 minute less penalty than ◔ Pacmen •••
[14:17]  UH++ , ◔ Pacmen ••• and Limitless are leading in that order with 3 , 3 and 2 solved problems in that order.
[14:20]  A guest contestant DECB (Daniel Enrique Cordovés Borroto) solved problem A and is now on top of the ranking with 3 problems solved but only 92 minutes of penalty .
[14:25]  UH++ solves also problem A and returns to the 1st place.
[14:26]  They have now 4 solved problems J , H , F and A , which are the only problems that have been solved so far.
[14:45]  ◔ Pacmen ••• keeps the good track and becomes the first team to solve problem K , now they have 4 problems solved and move up to the 2nd position of the unified ranking . They are leading the Dominican finals .
[14:50]  3N1?M4 also solves problem K and moves up to the 2nd position with 4 solved problems.
[14:55]  Team3C1 and ZForC solved problem G . This problem has not been solved by the teams that are currently leading .
[15:00]  ◔ Pacmen ••• got another . This time in problem A . They moved up to the 1st place and became the first team to solve 5 problems .
[15:05]  The standing is moving all the time and there is no clear leader. Now UH++ solved problem K and has also 5 solved problems but with the less penalty. They moved up to the 1st place and ◔ Pacmen ••• is now 2nd .
[15:10]  So far 6 problems J , H , F , A , K and G have been solved.
[15:10]  The leading team UH++ have solved all of them except G , they are trying to solve B but got wrong answer .
[15:15]  Limitless solves problem K and moves up to the 4th position. They are still trying to solve problem D .
[15:15]  The team that won the local contests UH_wake_me_up! didn't have a good start but they are slowly moving to the top. They are now at the 7th position with 4 solved problems.
[15:20]  UH++ finally solves problem B and stays at the top of the ranking with 6 solved problems . Now they have 1 solved problem more than the team at the 2nd place ◔ Pacmen ••• . Since UH++ has low penalty time, ◔ Pacmen ••• needs to solve at least 2 more problems to move up to the 1st position.
[15:35]  OkF solves problem J and becomes the first team from Puerto Rico in solving a problem. They are leading now the Puerto Rican finals .
[15:45]  Team ◔ Pacmen ••• solves their 6th problem B but stays at the 2nd place because of the penalty. They have the same amount of solved problems as the 1st place UH++ but with 15 minutes more of penalty time. The picture below shows the team in action:
[16:05]  UH++ solved problem G and has now 7 solved problems. They solved it with only one try , that means that the other teams that have 6 problems need to solve at least 2 problems to move up to the 1st position. It's early to make any predictions but it seems that they have a very good chance to win.
[16:10]  ◔ Pacmen ••• is now trying to solve problem D , this problem has not been solved so far.
[16:15]  The frozen time has just started. From now on the ranking won't be updated anymore. We will have to wait until the end to find out the winners .
[16:25]  The top10 before the frozen time is:
Rank  Team  Problems  Penalty 
1 
UH++

A
,
B
,
F
,
G
,
H
,
J
,
K

614 
2 
◔ Pacmen •••

A
,
B
,
F
,
H
,
J
,
K

462 
3 
The Avengers
(guest)

A
,
F
,
G
,
H
,
J
,
K

578 
4 
DECB
(guest)

A
,
F
,
G
,
H
,
J
,
K

618 
5 
UH_RELOADED

B
,
F
,
G
,
H
,
J
,
K

705 
6 
3N1?M4

F
,
G
,
H
,
J
,
K

340 
7 
UH_wake_me_up!

A
,
F
,
H
,
J
,
K

521 
8 
Los Retirados

F
,
G
,
H
,
J
,
K

526 
9 
Limitless

F
,
H
,
J
,
K

274 
10 
ZForC

F
,
G
,
H
,
J

317 
[16:45]  And we finally got a picture from the leading team (before the frozen time) UH++
[17:15]  The contest is over! The standing will remain frozen until 6:00 pm (Cuban local time). Come back later to find out the winners . The standing will be unfrozen using the dancing scoreboard. How many teams changed their positions during the frozen time? After 6:00 pm we will post a video with the results . See you!
[18:30]  The standing is now unfrozen ! Watch the video to find out the winners... or go directly to the final standing .
Muy buena editorial. Quisiera agregar algo para los lectores:
 Problema B: Creo que sería bueno resolver el problema asumiendo que todos los elementos son distintos y después analizar cómo modificar esa solución para resolver el problema con elementos repetidos.
 Problema C: Este link puede ser de ayuda: https://math.stackexchange.com/a/475219
 Problema I: Excelente el paper referenciado. Tener en cuenta que al implementar algoritmos con la idea de "rotating callipers" no es necesario calcular la amplitud de los ángulos (link que puede ser de ayuda: https://codeforces.com/blog/entry/48868). La segunda parte de la solución se puede resolver con "Optimal Merge Pattern" (al estilo "código Huffman"), donde inicialmente tenemos un conjunto por cada color.