[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / qst / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vip /vp / vr / w / wg / wsg / wsr / x / y ] [Search | Home]
4Archive logo
Alright /sci/, let's do some logic puzzles.
If images are not shown try to refresh the page. If you like this website, please disable any AdBlock software!

You are currently reading a thread in /sci/ - Science & Math

Thread replies: 23
Thread images: 1
File: logic dot jaypeg.jpg (39 KB, 570x377) Image search: [iqdb] [SauceNao] [Google]
logic dot jaypeg.jpg
39 KB, 570x377
Alright /sci/, let's do some logic puzzles.

>You have to guess the spelling of a foreign man's name. You know that the name is a string of 8 English letters (no numbers or special characters are included). However, the man will only answer "Yes" or "No" questions about his name. What is the fewest number of questions you can ask him in order to guess his name?
>>
If we talk about real names (ones that are/were already given to somebody at birth) then basic binary search through alphabet until using list of names becomes more effective ( for example if its male name and first four letters are alad then you might as well try asking if its aladin)

Or at least that's what i think on avarage would be the most efficient
>>
>>7808488
Does his name have to be discovered in the form of a question, like "is your name _____?" Or do you simply have to produce the name on your own and say it for it to count?

If the latter is true, the answer is zero, since you could technically not ask a single question and run through every possible combination of the 8 letters algorithmically until you get it right.
>>
>>7808488
If his name is actually a name and not just a random string of 8 characters then:

Get a list of all names. You assume this list includes all names.

Reduce the list to only male names.

Start randomly checking (as in is it b? c?, etc.) for the first letter.

Reduce list to only names who start with this letter

Randomly check for the last letters of names that start with the first letter.

Reduce list to only names that end with that letter

Repeat process by then going to the second letter and then the second before last letter, then third letter and so on until your list is reduced to one entry.

How many tries would this take? I don't know, I don't have the list.

gg well played.
>>
>>7808696
If you assume the name will be on the list, you could just perform a binary search.
>>
>>7808696
We can also drastically decrease the size of the name list by deductive reasoning. The man is foreign (foreign to the USA I'm assuming, which may be an invalid assumption, but I'm going with it) and yet his name contains only 8 letters from the 26 character "English" alphabet -- no special characters, so this bars diacritics (accent marks). A good question to start with would be "are you from the United Kingdom?" If no, "are you from Canada?" etc. As soon as you can deduce his country of origin, which shouldn't take long since very few countries outside of America use the English alphabet with no special characters, then you can use a much smaller list of names from which to guess.

Obviously people can have names derived from all countries and origins, but I'm guessing that the mention of him being foreign is significant to the value of his name.
>>
>>7808488
You should have asked "what is the minimum number of questions that will guarantee a correct answer"
>>
These sound less like logic puzzles and more like riddles. These types of questions basically require a creative solution that involves a weird re-interpretation of the problem
>>
>>7808488

5
>>
>>7808656
>>7808696
>>7808737
Guys shut up. The answer is 38. If you don't know why, you probably shouldn't be here.
>>
>>7808777

No wait, 40
>>
>>7808488

Just 1, fucking morons.
>>
>>7808488

>in order to guess

Just looking at the language, it's silly. You can ask just one question to be able to guess his name.

But let's assume OP's puzzle actually should say "guess accurately", well how does one define an accurate guess? An accurate guess would mean that there is no chance of failure, right?

So in that case, you would need to painfully find each letter with 26 questions for each letter. It is possible that his name's letters are always the last letter of the 26 letters you ask.

This question seems too vague, but I'm looking forward to the answer.
>>
>>7808782
I can do it in 30 flat. You REALLY shouldn't be here.
>>
>>7808488
>does Your name starts with a letter between a-f?
>does Your name starts with a letter between g-l?
>...
>does Your name ends with a letter between a-f?
>does Your name ends with a letter between g-l?
>...
then just compare a list of names
>>
>>7808488
The answer is somewhere between 1 and 26^8 guesses.
>>
>>7808488
I would think 38 yes-no questions would be the fewest number guaranteed to reduce 26^8 possible names to 1 name.
>>
>>7809229
This. Seriously guys, this is basic information theory.
26 letters, 8 times. [math] \log_2{26^8} = 8 \log_2{26} = 37.6... [/math]
This is assuming all the letters are equiprobable and independent, which is never the case of course, in any language. In practice it would be lower, but we can't know how much unless we know what the language is.
>>
>>7808488
homework thread in disguise
>>
>>7808488
>fewest number
The fewest number is 1 guess, I just need to get lucky :^)
>>
>>7810518
Same guy.
If we assume a language has around 2048 first names, which is a high estimate including nicknames and diminutives, a ballpark estimate of the number of questions in practice would be, [math] \log_2{(2048)} = 11 [/math] questions.
>>
>>7808488

Fewest is 1.

Otherwise you'd start by asking 26x8

But it's definitely less because you know some of the letters already. You'll probably ask fewer than 20
>>
>>7808488
Just ask if his name is Muhammed.
Thread replies: 23
Thread images: 1
Thread DB ID: 468130



[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / qst / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vip /vp / vr / w / wg / wsg / wsr / x / y] [Search | Home]

[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / qst / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vip /vp / vr / w / wg / wsg / wsr / x / y] [Search | Home]

All trademarks and copyrights on this page are owned by their respective parties. Images uploaded are the responsibility of the Poster. Comments are owned by the Poster.
This is a 4chan archive - all of the shown content originated from that site. This means that 4Archive shows their content, archived. If you need information for a Poster - contact them.
If a post contains personal/copyrighted/illegal content, then use the post's [Report] link! If a post is not removed within 24h contact me at [email protected] with the post's information.