mersenneforum.org  

Go Back   mersenneforum.org > Fun Stuff > Puzzles

Reply
 
Thread Tools
Old 2020-04-12, 22:10   #34
0scar
 
Jan 2020

2710 Posts
Default

Quote:
Originally Posted by Kebbaj View Post
I get with the example of the Excel file attached, that after 10 days all cities are 100% contaminated.
Where does the 29% come from? Something that I am not well understood?
I didn't look at your Excel file before.
According to your computations, after ten days the cities are contaminated ABOVE 100%.
You noticed it, and you hid it with well placed if statements.
But the main problem is that you are counting many infection events more than once.

As an example, on day 2 the correct values should be (using your format):
A = 10000,
B = 1900,
C = 1981,
D = 1981,
E = 199.

Last fiddled with by 0scar on 2020-04-12 at 22:19 Reason: Adding correct values on day 2
0scar is offline   Reply With Quote
Old 2020-04-13, 08:46   #35
Kebbaj
 
Kebbaj's Avatar
 
"Kebbaj Reda"
May 2018
Casablanca, Morocco

728 Posts
Default

Quote:
Originally Posted by 0scar View Post
I
As an example, on day 2 the correct values should be (using your format):
A = 10000,
B = 1900,
C = 1981,
D = 1981,
E = 199.
City B for example
Day 0 infection B: 0
Day 1 infection B: 1000
(10000 * 0.1)
Day 2 infection B: 2000
(1000(day 1) + 10000 * 0.1 = 2000)

Where did your 1900 come from for city B.
Please answer with calculations.

Last fiddled with by Kebbaj on 2020-04-13 at 08:49
Kebbaj is offline   Reply With Quote
Old 2020-04-13, 09:07   #36
0scar
 
Jan 2020

33 Posts
Default

Quote:
Originally Posted by Kebbaj View Post
City B for example
Day 0 infection B: 0
Day 1 infection B: 1000
(10000 * 0.1)
Day 2 infection B: 2000
(1000(day 1) + 10000 * 0.1 = 2000)

Where did your 1900 come from for city B.
Please answer with calculations.
On day 2, city B, only the 9000 people still healthy can be infected (from A only):
1000+9000*0.1= 1900.
Otherwise, some people infected on previous days are counted over and over again, quickly exceeding 100%.
0scar is offline   Reply With Quote
Old 2020-04-13, 10:19   #37
Kebbaj
 
Kebbaj's Avatar
 
"Kebbaj Reda"
May 2018
Casablanca, Morocco

2×29 Posts
Thumbs up

Quote:
Originally Posted by 0scar View Post
On day 2, city B, only the 9000 people still healthy can be infected (from A only):
1000+9000*0.1= 1900.
Otherwise, some people infected on previous days are counted over and over again, quickly exceeding 100%.
Yes your reason is better than mine. I had seen that the source city A with a high viral load of 10000 infected cases can count 1000 healthy cases in city B.
Kebbaj is offline   Reply With Quote
Old 2020-04-14, 16:40   #38
uau
 
Jan 2017

79 Posts
Default

Anyone have an idea what the newly added bonus thing means? It says:
Quote:
Bonus '*' for getting the closest to 70% in 19 days; and ’**' for getting even closer.
"even closer"? What does that mean? Only one person has '**'; with the limited space for potential solutions, it doesn't seem plausible that everyone else would have failed to find the best possible solution...
uau is offline   Reply With Quote
Old 2020-04-14, 17:30   #39
0scar
 
Jan 2020

110112 Posts
Default

Quote:
Originally Posted by uau View Post
Anyone have an idea what the newly added bonus thing means? It says:
"even closer"? What does that mean? Only one person has '**'; with the limited space for potential solutions, it doesn't seem plausible that everyone else would have failed to find the best possible solution...
I think that someone didn't stop on day 10 or on day 19, but he always checked every t until p >=.7 was reached. And he eventually found some p very, very close.
My guess: somewhere before day 81.
0scar is offline   Reply With Quote
Old 2020-04-27, 07:44   #40
Dieter
 
Oct 2017

2·72 Posts
Default

Are there many equivalent adjacency matrices with 70,0074873 % after 10 days or is my code wrong?
Dieter is offline   Reply With Quote
Old 2020-04-27, 08:21   #41
SmartMersenne
 
Sep 2017

10101102 Posts
Default

Quote:
Originally Posted by Dieter View Post
Are there many equivalent adjacency matrices with 70,0074873 % after 10 days or is my code wrong?
Not sure, but there must be many equivalent matrices, at least the permutations of all the rest of the points except the originating city, minus the degenerate cases due to isomorphic connections. If the graph is dense, there will be many degenerate cases, but if the it is sparse, you will have little number of degenerate cases.
SmartMersenne is offline   Reply With Quote
Old 2020-04-27, 16:30   #42
tgan
 
Jul 2015

17 Posts
Default

Yes i am getting this result also not sure if it is good enough
tgan is offline   Reply With Quote
Old 2020-04-27, 18:31   #43
yae9911
 
yae9911's Avatar
 
"Hugo"
Jul 2019
Germany

31 Posts
Default

Quote:
Originally Posted by tgan View Post
Yes i am getting this result also not sure if it is good enough
The optimum result of 70.007... for 10 days and 8 nodes corresponds to only one unlabeled connected graph. There are several ways to chose the root node in this graph all leading to the same probability of "all nodes infected". Since the updated description says
Quote:
We were seeking the answer of Day 19 (which can give a solution with a better approximation), but we also accepted answers for Day 10.
is written in past tense, it is not clear if this means that they are still accepting the best result for 10 days, which is not accurate enough when rounded to 70.01.
yae9911 is offline   Reply With Quote
Old 2020-04-27, 20:35   #44
Dieter
 
Oct 2017

2·72 Posts
Default

Quote:
Originally Posted by yae9911 View Post
The optimum result of 70.007... for 10 days and 8 nodes corresponds to only one unlabeled connected graph. There are several ways to chose the root node in this graph all leading to the same probability of "all nodes infected". Since the updated description says is written in past tense, it is not clear if this means that they are still accepting the best result for 10 days, which is not accurate enough when rounded to 70.01.
We were seeking the answer of Day 19 (which can give a solution with a better approximation), but we also accepted answers for Day 10.

Could that be „Konjunktiv“? We also would accept... (wir würden auch...akzeptieren)? A question for a native speaker!

Last fiddled with by Dieter on 2020-04-27 at 20:38 Reason: Complement
Dieter is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
U.S. Electile Dementia paralytica 2020 ewmayer Soap Box 542 2020-11-25 21:42
2020 project goals gd_barnes Conjectures 'R Us 4 2020-09-23 08:59
March 2020 what Puzzles 1 2020-04-24 05:46
February 2020 what Puzzles 20 2020-03-04 07:55
January 2020 what Puzzles 21 2020-02-02 14:11

All times are UTC. The time now is 13:44.

Thu Nov 26 13:44:03 UTC 2020 up 77 days, 10:55, 3 users, load averages: 0.90, 1.25, 1.40

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.