Wolves and sheep The 2019 Stack Overflow Developer Survey Results Are In ...
Did the new image of black hole confirm the general theory of relativity?
Can withdrawing asylum be illegal?
When did F become S in typeography, and why?
Searching for a differential characteristic (differential cryptanalysis)
Is above average number of years spent on PhD considered a red flag in future academia or industry positions?
He got a vote 80% that of Emmanuel Macron’s
Does Parliament hold absolute power in the UK?
What is special about square numbers here?
Does Parliament need to approve the new Brexit delay to 31 October 2019?
Why is superheterodyning better than direct conversion?
What is this lever in Argentinian toilets?
Sort a list of pairs representing an acyclic, partial automorphism
Is every episode of "Where are my Pants?" identical?
What's the point in a preamp?
Relations between two reciprocal partial derivatives?
I could not break this equation. Please help me
What can I do if neighbor is blocking my solar panels intentionally?
What aspect of planet Earth must be changed to prevent the industrial revolution?
Did God make two great lights or did He make the great light two?
Can the DM override racial traits?
Why did all the guest students take carriages to the Yule Ball?
How to delete random line from file using Unix command?
How should I replace vector<uint8_t>::const_iterator in an API?
The following signatures were invalid: EXPKEYSIG 1397BC53640DB551
Wolves and sheep
The 2019 Stack Overflow Developer Survey Results Are In
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Fastest way to collect an arbitrary armyMiddle weight puzzleA puzzle of trust and lies, allies and spiesCooperative guessing against an evil godLabeling wires in a *damaged* bundleMonopoly Game Show: Is there a winning strategy?Picking A Number GamePrisoners and minority votingMove 10 sheep on another shoreBlindfold Bingo
$begingroup$
All the sheep were living peacefully in the Land of Shewo. But suddenly they were struck by a danger. A few wolves dressed up as sheep entered the territory of Shewo and started killing the sheep one by one.
To find a solution to this misery, the king of Shewo called upon all of his sheep to the palace hall. He made the following announcement:
From my secret sources, I came to know that the total number of 'sheep' (including the wolves) now present in my kingdom is 100. Among which 5 are wolves. Our doctors have come up with a very expensive blood test which could be used to differentiate the wolves and sheep.
Each test costs 1000$ and we don't have enough funds to test all the 100 'sheep'.
I discussed with our ministers and came to know that the tests can be done on pooled bloodsamples. i.e., I can collect bloods from any number of 'sheep' and mix them. Then if I test the mixture, I will get a positive result if the mixture contain blood from any wolf. I will get a negative result if all the samples are from actual sheep.
One caveat is that the test results are available to you after all the tests are done!
Now , I am looking for ideas where I can find ALL the wolves in minimum number of pooled tests. I request the brilliant young minds of this land to come up with a testing strategy.
Can you help the king by devising a strategy?
strategy combinatorics algorithm
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
$endgroup$
add a comment |
$begingroup$
All the sheep were living peacefully in the Land of Shewo. But suddenly they were struck by a danger. A few wolves dressed up as sheep entered the territory of Shewo and started killing the sheep one by one.
To find a solution to this misery, the king of Shewo called upon all of his sheep to the palace hall. He made the following announcement:
From my secret sources, I came to know that the total number of 'sheep' (including the wolves) now present in my kingdom is 100. Among which 5 are wolves. Our doctors have come up with a very expensive blood test which could be used to differentiate the wolves and sheep.
Each test costs 1000$ and we don't have enough funds to test all the 100 'sheep'.
I discussed with our ministers and came to know that the tests can be done on pooled bloodsamples. i.e., I can collect bloods from any number of 'sheep' and mix them. Then if I test the mixture, I will get a positive result if the mixture contain blood from any wolf. I will get a negative result if all the samples are from actual sheep.
One caveat is that the test results are available to you after all the tests are done!
Now , I am looking for ideas where I can find ALL the wolves in minimum number of pooled tests. I request the brilliant young minds of this land to come up with a testing strategy.
Can you help the king by devising a strategy?
strategy combinatorics algorithm
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
$endgroup$
$begingroup$
This is close to a covering design (Lotto wheel) problem.
$endgroup$
– Arnaud Mortier
3 hours ago
1
$begingroup$
First of all, does the government have enough funds to test 99 of the sheep? Because that would work, at a cost of $99,000. Congrats, you just saved 1,000 bucks.
$endgroup$
– user45266
1 hour ago
1
$begingroup$
Alternatively, you know the location of all 5 wolves. Take initiative and slaughter all 100. Now you have no more wolves, and food for a good while to come.
$endgroup$
– user45266
1 hour ago
add a comment |
$begingroup$
All the sheep were living peacefully in the Land of Shewo. But suddenly they were struck by a danger. A few wolves dressed up as sheep entered the territory of Shewo and started killing the sheep one by one.
To find a solution to this misery, the king of Shewo called upon all of his sheep to the palace hall. He made the following announcement:
From my secret sources, I came to know that the total number of 'sheep' (including the wolves) now present in my kingdom is 100. Among which 5 are wolves. Our doctors have come up with a very expensive blood test which could be used to differentiate the wolves and sheep.
Each test costs 1000$ and we don't have enough funds to test all the 100 'sheep'.
I discussed with our ministers and came to know that the tests can be done on pooled bloodsamples. i.e., I can collect bloods from any number of 'sheep' and mix them. Then if I test the mixture, I will get a positive result if the mixture contain blood from any wolf. I will get a negative result if all the samples are from actual sheep.
One caveat is that the test results are available to you after all the tests are done!
Now , I am looking for ideas where I can find ALL the wolves in minimum number of pooled tests. I request the brilliant young minds of this land to come up with a testing strategy.
Can you help the king by devising a strategy?
strategy combinatorics algorithm
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
$endgroup$
All the sheep were living peacefully in the Land of Shewo. But suddenly they were struck by a danger. A few wolves dressed up as sheep entered the territory of Shewo and started killing the sheep one by one.
To find a solution to this misery, the king of Shewo called upon all of his sheep to the palace hall. He made the following announcement:
From my secret sources, I came to know that the total number of 'sheep' (including the wolves) now present in my kingdom is 100. Among which 5 are wolves. Our doctors have come up with a very expensive blood test which could be used to differentiate the wolves and sheep.
Each test costs 1000$ and we don't have enough funds to test all the 100 'sheep'.
I discussed with our ministers and came to know that the tests can be done on pooled bloodsamples. i.e., I can collect bloods from any number of 'sheep' and mix them. Then if I test the mixture, I will get a positive result if the mixture contain blood from any wolf. I will get a negative result if all the samples are from actual sheep.
One caveat is that the test results are available to you after all the tests are done!
Now , I am looking for ideas where I can find ALL the wolves in minimum number of pooled tests. I request the brilliant young minds of this land to come up with a testing strategy.
Can you help the king by devising a strategy?
strategy combinatorics algorithm
strategy combinatorics algorithm
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
asked 4 hours ago
Jyotish RobinJyotish Robin
515112
515112
$begingroup$
This is close to a covering design (Lotto wheel) problem.
$endgroup$
– Arnaud Mortier
3 hours ago
1
$begingroup$
First of all, does the government have enough funds to test 99 of the sheep? Because that would work, at a cost of $99,000. Congrats, you just saved 1,000 bucks.
$endgroup$
– user45266
1 hour ago
1
$begingroup$
Alternatively, you know the location of all 5 wolves. Take initiative and slaughter all 100. Now you have no more wolves, and food for a good while to come.
$endgroup$
– user45266
1 hour ago
add a comment |
$begingroup$
This is close to a covering design (Lotto wheel) problem.
$endgroup$
– Arnaud Mortier
3 hours ago
1
$begingroup$
First of all, does the government have enough funds to test 99 of the sheep? Because that would work, at a cost of $99,000. Congrats, you just saved 1,000 bucks.
$endgroup$
– user45266
1 hour ago
1
$begingroup$
Alternatively, you know the location of all 5 wolves. Take initiative and slaughter all 100. Now you have no more wolves, and food for a good while to come.
$endgroup$
– user45266
1 hour ago
$begingroup$
This is close to a covering design (Lotto wheel) problem.
$endgroup$
– Arnaud Mortier
3 hours ago
$begingroup$
This is close to a covering design (Lotto wheel) problem.
$endgroup$
– Arnaud Mortier
3 hours ago
1
1
$begingroup$
First of all, does the government have enough funds to test 99 of the sheep? Because that would work, at a cost of $99,000. Congrats, you just saved 1,000 bucks.
$endgroup$
– user45266
1 hour ago
$begingroup$
First of all, does the government have enough funds to test 99 of the sheep? Because that would work, at a cost of $99,000. Congrats, you just saved 1,000 bucks.
$endgroup$
– user45266
1 hour ago
1
1
$begingroup$
Alternatively, you know the location of all 5 wolves. Take initiative and slaughter all 100. Now you have no more wolves, and food for a good while to come.
$endgroup$
– user45266
1 hour ago
$begingroup$
Alternatively, you know the location of all 5 wolves. Take initiative and slaughter all 100. Now you have no more wolves, and food for a good while to come.
$endgroup$
– user45266
1 hour ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
Here's my shot at it:
Pool 50 of the sheep. Of those 50, if the result comes back positive (wolf detected), split in half again, testing 25 pooled together. If this comes back positive, either 12 or 13 ofthe positive group. You see where this is going. Any negative results rule out all sheep in that group. Worst case scenario, it takes 54 tests (see image for explanation). Best case scenario, you get 14 tests. Price range: 14,000 - 54,000 dollars.
Not sure yet of the expected average, but I know this is better than 99 tests on average.
Diagram:
If this isn't the optimal solution, then my best bet on how to improve it would be to:
split into 1/5 the size of each group.
answered 1 hour ago
user45266user45266
32514
$endgroup$
$begingroup$
I do not consider it much of a spoiler (there must be better algorithms) but the worst case scenario can be easily reduced to 35 tests. rot13(Qb ovanel frnepurf sbe bar jbys. Rnpu frnepu vf qbar ba nyy gur furrc zvahf jbysf sbhaq va gur cerivbhf frnepurf. Lbh jvyy arrq 5 frnepurf. Rnpu frnepu jvyy gnxr ng zbfg 7 grfgf. Fb gur jbefg pnfr fpranevb vf 35 grfgf).
$endgroup$
– ppgdev
51 mins ago
$begingroup$
Wait a minute, how would that work? Could you be a little more specific?
$endgroup$
– user45266
49 mins ago
$begingroup$
@ppgdev Like starting with 100, you split the group into 5 groups? What do you mean?
$endgroup$
– user45266
47 mins ago
$begingroup$
I moved my comment into an upper bound answer, with a more detailed explanation.
$endgroup$
– ppgdev
31 mins ago
add a comment |
$begingroup$
There must be better algorithms, but just to put an upper bound on a solution, the worst case scenario can be reduced to
35 tests. Do binary searches for one wolf. Each search is done on all the sheep minus wolfs found in the previous searches. So the first binary search is done on a set of all 100 'sheep'. You will find a wolf in no more than 7 tests. The next binary search is done on remaining 99 sheep. And so on. You will need 5 binary searches. Each search will take at most 7 tests. So the worst case scenario is 35 tests.
answered 32 mins ago
ppgdevppgdev
41516
$endgroup$
$begingroup$
Unfortunately that will not actually work. The problem states you will only get the results of the tests after all the tests have been done (maybe it takes a few days for the results to come through!), so you can’t base your second test on the results of the first one.
$endgroup$
– Amorydai
2 mins ago
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "559"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f81737%2fwolves-and-sheep%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Here's my shot at it:
Pool 50 of the sheep. Of those 50, if the result comes back positive (wolf detected), split in half again, testing 25 pooled together. If this comes back positive, either 12 or 13 ofthe positive group. You see where this is going. Any negative results rule out all sheep in that group. Worst case scenario, it takes 54 tests (see image for explanation). Best case scenario, you get 14 tests. Price range: 14,000 - 54,000 dollars.
Not sure yet of the expected average, but I know this is better than 99 tests on average.
Diagram:
If this isn't the optimal solution, then my best bet on how to improve it would be to:
split into 1/5 the size of each group.
answered 1 hour ago
user45266user45266
32514
$endgroup$
$begingroup$
I do not consider it much of a spoiler (there must be better algorithms) but the worst case scenario can be easily reduced to 35 tests. rot13(Qb ovanel frnepurf sbe bar jbys. Rnpu frnepu vf qbar ba nyy gur furrc zvahf jbysf sbhaq va gur cerivbhf frnepurf. Lbh jvyy arrq 5 frnepurf. Rnpu frnepu jvyy gnxr ng zbfg 7 grfgf. Fb gur jbefg pnfr fpranevb vf 35 grfgf).
$endgroup$
– ppgdev
51 mins ago
$begingroup$
Wait a minute, how would that work? Could you be a little more specific?
$endgroup$
– user45266
49 mins ago
$begingroup$
@ppgdev Like starting with 100, you split the group into 5 groups? What do you mean?
$endgroup$
– user45266
47 mins ago
$begingroup$
I moved my comment into an upper bound answer, with a more detailed explanation.
$endgroup$
– ppgdev
31 mins ago
add a comment |
$begingroup$
Here's my shot at it:
Pool 50 of the sheep. Of those 50, if the result comes back positive (wolf detected), split in half again, testing 25 pooled together. If this comes back positive, either 12 or 13 ofthe positive group. You see where this is going. Any negative results rule out all sheep in that group. Worst case scenario, it takes 54 tests (see image for explanation). Best case scenario, you get 14 tests. Price range: 14,000 - 54,000 dollars.
Not sure yet of the expected average, but I know this is better than 99 tests on average.
Diagram:
If this isn't the optimal solution, then my best bet on how to improve it would be to:
split into 1/5 the size of each group.
answered 1 hour ago
user45266user45266
32514
$endgroup$
$begingroup$
I do not consider it much of a spoiler (there must be better algorithms) but the worst case scenario can be easily reduced to 35 tests. rot13(Qb ovanel frnepurf sbe bar jbys. Rnpu frnepu vf qbar ba nyy gur furrc zvahf jbysf sbhaq va gur cerivbhf frnepurf. Lbh jvyy arrq 5 frnepurf. Rnpu frnepu jvyy gnxr ng zbfg 7 grfgf. Fb gur jbefg pnfr fpranevb vf 35 grfgf).
$endgroup$
– ppgdev
51 mins ago
$begingroup$
Wait a minute, how would that work? Could you be a little more specific?
$endgroup$
– user45266
49 mins ago
$begingroup$
@ppgdev Like starting with 100, you split the group into 5 groups? What do you mean?
$endgroup$
– user45266
47 mins ago
$begingroup$
I moved my comment into an upper bound answer, with a more detailed explanation.
$endgroup$
– ppgdev
31 mins ago
add a comment |
$begingroup$
Here's my shot at it:
Pool 50 of the sheep. Of those 50, if the result comes back positive (wolf detected), split in half again, testing 25 pooled together. If this comes back positive, either 12 or 13 ofthe positive group. You see where this is going. Any negative results rule out all sheep in that group. Worst case scenario, it takes 54 tests (see image for explanation). Best case scenario, you get 14 tests. Price range: 14,000 - 54,000 dollars.
Not sure yet of the expected average, but I know this is better than 99 tests on average.
Diagram:
If this isn't the optimal solution, then my best bet on how to improve it would be to:
split into 1/5 the size of each group.
answered 1 hour ago
user45266user45266
32514
$endgroup$
Here's my shot at it:
Pool 50 of the sheep. Of those 50, if the result comes back positive (wolf detected), split in half again, testing 25 pooled together. If this comes back positive, either 12 or 13 ofthe positive group. You see where this is going. Any negative results rule out all sheep in that group. Worst case scenario, it takes 54 tests (see image for explanation). Best case scenario, you get 14 tests. Price range: 14,000 - 54,000 dollars.
Not sure yet of the expected average, but I know this is better than 99 tests on average.
Diagram:
If this isn't the optimal solution, then my best bet on how to improve it would be to:
split into 1/5 the size of each group.
answered 1 hour ago
user45266user45266
32514
answered 1 hour ago
user45266user45266
32514
answered 1 hour ago
user45266user45266
32514
answered 1 hour ago
user45266user45266
32514
32514
$begingroup$
I do not consider it much of a spoiler (there must be better algorithms) but the worst case scenario can be easily reduced to 35 tests. rot13(Qb ovanel frnepurf sbe bar jbys. Rnpu frnepu vf qbar ba nyy gur furrc zvahf jbysf sbhaq va gur cerivbhf frnepurf. Lbh jvyy arrq 5 frnepurf. Rnpu frnepu jvyy gnxr ng zbfg 7 grfgf. Fb gur jbefg pnfr fpranevb vf 35 grfgf).
$endgroup$
– ppgdev
51 mins ago
$begingroup$
Wait a minute, how would that work? Could you be a little more specific?
$endgroup$
– user45266
49 mins ago
$begingroup$
@ppgdev Like starting with 100, you split the group into 5 groups? What do you mean?
$endgroup$
– user45266
47 mins ago
$begingroup$
I moved my comment into an upper bound answer, with a more detailed explanation.
$endgroup$
– ppgdev
31 mins ago
add a comment |
$begingroup$
I do not consider it much of a spoiler (there must be better algorithms) but the worst case scenario can be easily reduced to 35 tests. rot13(Qb ovanel frnepurf sbe bar jbys. Rnpu frnepu vf qbar ba nyy gur furrc zvahf jbysf sbhaq va gur cerivbhf frnepurf. Lbh jvyy arrq 5 frnepurf. Rnpu frnepu jvyy gnxr ng zbfg 7 grfgf. Fb gur jbefg pnfr fpranevb vf 35 grfgf).
$endgroup$
– ppgdev
51 mins ago
$begingroup$
Wait a minute, how would that work? Could you be a little more specific?
$endgroup$
– user45266
49 mins ago
$begingroup$
@ppgdev Like starting with 100, you split the group into 5 groups? What do you mean?
$endgroup$
– user45266
47 mins ago
$begingroup$
I moved my comment into an upper bound answer, with a more detailed explanation.
$endgroup$
– ppgdev
31 mins ago
$begingroup$
I do not consider it much of a spoiler (there must be better algorithms) but the worst case scenario can be easily reduced to 35 tests. rot13(Qb ovanel frnepurf sbe bar jbys. Rnpu frnepu vf qbar ba nyy gur furrc zvahf jbysf sbhaq va gur cerivbhf frnepurf. Lbh jvyy arrq 5 frnepurf. Rnpu frnepu jvyy gnxr ng zbfg 7 grfgf. Fb gur jbefg pnfr fpranevb vf 35 grfgf).
$endgroup$
– ppgdev
51 mins ago
$begingroup$
I do not consider it much of a spoiler (there must be better algorithms) but the worst case scenario can be easily reduced to 35 tests. rot13(Qb ovanel frnepurf sbe bar jbys. Rnpu frnepu vf qbar ba nyy gur furrc zvahf jbysf sbhaq va gur cerivbhf frnepurf. Lbh jvyy arrq 5 frnepurf. Rnpu frnepu jvyy gnxr ng zbfg 7 grfgf. Fb gur jbefg pnfr fpranevb vf 35 grfgf).
$endgroup$
– ppgdev
51 mins ago
$begingroup$
Wait a minute, how would that work? Could you be a little more specific?
$endgroup$
– user45266
49 mins ago
$begingroup$
Wait a minute, how would that work? Could you be a little more specific?
$endgroup$
– user45266
49 mins ago
$begingroup$
@ppgdev Like starting with 100, you split the group into 5 groups? What do you mean?
$endgroup$
– user45266
47 mins ago
$begingroup$
@ppgdev Like starting with 100, you split the group into 5 groups? What do you mean?
$endgroup$
– user45266
47 mins ago
$begingroup$
I moved my comment into an upper bound answer, with a more detailed explanation.
$endgroup$
– ppgdev
31 mins ago
$begingroup$
I moved my comment into an upper bound answer, with a more detailed explanation.
$endgroup$
– ppgdev
31 mins ago
add a comment |
$begingroup$
There must be better algorithms, but just to put an upper bound on a solution, the worst case scenario can be reduced to
35 tests. Do binary searches for one wolf. Each search is done on all the sheep minus wolfs found in the previous searches. So the first binary search is done on a set of all 100 'sheep'. You will find a wolf in no more than 7 tests. The next binary search is done on remaining 99 sheep. And so on. You will need 5 binary searches. Each search will take at most 7 tests. So the worst case scenario is 35 tests.
answered 32 mins ago
ppgdevppgdev
41516
$endgroup$
$begingroup$
Unfortunately that will not actually work. The problem states you will only get the results of the tests after all the tests have been done (maybe it takes a few days for the results to come through!), so you can’t base your second test on the results of the first one.
$endgroup$
– Amorydai
2 mins ago
add a comment |
$begingroup$
There must be better algorithms, but just to put an upper bound on a solution, the worst case scenario can be reduced to
35 tests. Do binary searches for one wolf. Each search is done on all the sheep minus wolfs found in the previous searches. So the first binary search is done on a set of all 100 'sheep'. You will find a wolf in no more than 7 tests. The next binary search is done on remaining 99 sheep. And so on. You will need 5 binary searches. Each search will take at most 7 tests. So the worst case scenario is 35 tests.
answered 32 mins ago
ppgdevppgdev
41516
$endgroup$
$begingroup$
Unfortunately that will not actually work. The problem states you will only get the results of the tests after all the tests have been done (maybe it takes a few days for the results to come through!), so you can’t base your second test on the results of the first one.
$endgroup$
– Amorydai
2 mins ago
add a comment |
$begingroup$
There must be better algorithms, but just to put an upper bound on a solution, the worst case scenario can be reduced to
35 tests. Do binary searches for one wolf. Each search is done on all the sheep minus wolfs found in the previous searches. So the first binary search is done on a set of all 100 'sheep'. You will find a wolf in no more than 7 tests. The next binary search is done on remaining 99 sheep. And so on. You will need 5 binary searches. Each search will take at most 7 tests. So the worst case scenario is 35 tests.
answered 32 mins ago
ppgdevppgdev
41516
$endgroup$
There must be better algorithms, but just to put an upper bound on a solution, the worst case scenario can be reduced to
35 tests. Do binary searches for one wolf. Each search is done on all the sheep minus wolfs found in the previous searches. So the first binary search is done on a set of all 100 'sheep'. You will find a wolf in no more than 7 tests. The next binary search is done on remaining 99 sheep. And so on. You will need 5 binary searches. Each search will take at most 7 tests. So the worst case scenario is 35 tests.
answered 32 mins ago
ppgdevppgdev
41516
answered 32 mins ago
ppgdevppgdev
41516
answered 32 mins ago
ppgdevppgdev
41516
answered 32 mins ago
ppgdevppgdev
41516
41516
$begingroup$
Unfortunately that will not actually work. The problem states you will only get the results of the tests after all the tests have been done (maybe it takes a few days for the results to come through!), so you can’t base your second test on the results of the first one.
$endgroup$
– Amorydai
2 mins ago
add a comment |
$begingroup$
Unfortunately that will not actually work. The problem states you will only get the results of the tests after all the tests have been done (maybe it takes a few days for the results to come through!), so you can’t base your second test on the results of the first one.
$endgroup$
– Amorydai
2 mins ago
$begingroup$
Unfortunately that will not actually work. The problem states you will only get the results of the tests after all the tests have been done (maybe it takes a few days for the results to come through!), so you can’t base your second test on the results of the first one.
$endgroup$
– Amorydai
2 mins ago
$begingroup$
Unfortunately that will not actually work. The problem states you will only get the results of the tests after all the tests have been done (maybe it takes a few days for the results to come through!), so you can’t base your second test on the results of the first one.
$endgroup$
– Amorydai
2 mins ago
add a comment |
Thanks for contributing an answer to Puzzling Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f81737%2fwolves-and-sheep%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
This is close to a covering design (Lotto wheel) problem.
$endgroup$
– Arnaud Mortier
3 hours ago
1
$begingroup$
First of all, does the government have enough funds to test 99 of the sheep? Because that would work, at a cost of $99,000. Congrats, you just saved 1,000 bucks.
$endgroup$
– user45266
1 hour ago
1
$begingroup$
Alternatively, you know the location of all 5 wolves. Take initiative and slaughter all 100. Now you have no more wolves, and food for a good while to come.
$endgroup$
– user45266
1 hour ago