Searches for search. Count counting on request pages
To quickly find information on the Internet use search queries. Search query is a set keywordsconnected by signatures of logical operations and, or not.
The priority of performing operations, if there are no special brackets, the following: first not, then, and then or.
It is necessary to understand that the operation and (simultaneous execution of conditions) reduces the amount of the result obtained, and the operation or (execution of at least one of the conditions) on the contrary increases the volume.
If the phrase is in quotes in the query, the system will look exactly the whole phrase.
1. Location of queries ascending (descending)
Operation "And" (&) indicates the simultaneous presence of keywords in the required documents, and therefore reduces the number of information found. The more keywords are connected by the operation "and", the less the amount of information found. Conversely, the operation "or" (|) indicates the presence of at least one keyword in the desired documents, and therefore increases the number of information found.
Example 1.
The table shows requests to the search server. Place the designations of requests in ascending order of the number of pages that will find a search server for each request.
A) abstract | Mathematics | Gauss
B) abstract | Mathematics | Gauss | method
C) abstract | mathematics
D) Abstract & Mathematics & Gauss
Decision:
The smallest number of pages will be selected on request with the greatest number Operations "and" (query d), the largest number of pages will be selected on request with the highest number of operations "or" (query b). On request, more pages will be selected than on request B, because Request A contains more keywords related to "or" operation.
Answer: Gvab
2. Counting found on request pages
This type of tasks is usually solved by the system of equations. Suggest a more visual and easy way.
The principle of selection of information on search queries well illustrates the Euler-Venna diagram (Euler circles). On the set diagram are depicted by intersecting circles. Operation "And" (&) is the crossing of circles, and the operation "or" (|) is a combination of circles.
For example, we denote the circles of many apples, pears, bananas. On request, apples & pears & bananas will be selected the intersection (general part) of all three circles:
On request Apples | Pears will be selected combining two circles:
Example 2.
How many pages (in thousands) will be found on request chess?
Decision:
Draw an Euler-Venna chart. The task solution is consisting of counting the number of pages corresponding to each region limited by the lines:
The query of Chess & Tennis corresponds to the average area (1000 thousand pages), and the query of tennis is the entire right circle (5500 thousand pages).
Then the right "cropped circle" is 5500-1000 \u003d 4500:
Request Chess | Tennis corresponds both circles (7770), then the left "cropped circle" is 7770-5500 \u003d 2270
So, we counted the number of pages for each limited area lines:
It is easy to see that at the request of chess will be found 2270 + 1000 \u003d 3270 thousand pages.
Answer: 3270.
Example 3.
The table provides requests and number of pages that found a search server for these requests in some Internet segment:
How many pages (in thousands) will be found on request
Moscow & Paris | London)
Decision:
As in the previous task, draw the Euler-Venna chart and consider the number of pages corresponding to each known area limited by the lines:
It is easy to see that the request Moscow & (Paris | London) corresponds to the area.
Task wording: Searches for the search server. Place the queries numbers in ascending order of (descending) number of pages that will find a computer for each request. For notation logical operation "Or" in the query uses the symbol |, and for the logical operation "and" - &.
The task is included in the EGE on computer science for grade 11 at number 17 (queries for search engines Using logical expressions).
Consider how similar tasks are solved on the examples. When solving, it should be borne in mind that "or" always increases the number of results, and "and" reduces.
Description of the task 1:
The following are queries for the search server. Position query numbers in an increase in the number of pages that will find a search server for each request. To denote the logical operation "or" in the query, the symbol is used |, and for the logical operation "and" - &.
- printers & Scanners & Sale
- printers & Sale
- printers | sale
- printers | Scanners | sale
Option 1
"Printers & Scanners & Sale" - information and printers and scanners should be present on each page. Since each "and" reduces the number of pages on request, the results will be found in the least.
Option 2.
"Printers & Sale" - information and printers and sale should be present on each page. Since "and" reduces the number of pages on request, the results will be found more than on the first request.
Option 3.
"Printers | Sale "- On each page there must be information or about printers, or for sale. Since "or" increases the number of pages on request, the results will be found more than the first two.
Option 4.
"Printers | Scanners | Sale "- On each page there must be information or about printers, or about scanners, or selling. Since each "or" increases the number of pages on request, the results will be found most.
Thus, the correct answer is 1234. Queries numbers are located in an increase in the number of pages that will find a search server for each request.
Answer: 1234.
An example of task 2:
The table shows requests to the search server. Place the queries numbers in order of increasing the number of pages that will find a search server for each request. To denote the logical operation "or" in the query, the symbol is used |, and for the logical operation "and" - &.
- painting & literature
- painting | literature
- painting | Literature | graphic arts
- painting & Literature & Graphics
Consider in detail each request for the search server.
Option 1
"Painting & Literature" - On each page there must be information about painting, and about literature. Since "and" reduces the number of pages on request, the results will be found less than according to the following request.
Option 2.
"Painting | Literature "- on each page there should be information or about painting, or about literature. Since "or" increases the number of pages on request, the results will be found more than the first request.
Option 3.
"Painting | Literature | Graphics "- On each page there should be information or painting, or about literature, or about the schedule. Since each "or" increases the number of pages on request, the results will be found most.
Option 4.
"Painting & Literature & Graphics" - on each page there should be information about painting, and literature, and about the schedule. Since each "and" reduces the number of pages on request, the results will be found in the least.
Thus, the correct answer is 4123. Request numbers are located in an increase in the number of pages that will find a search server for each request.
Answer: 4123.
An example of task 3:
Place the query numbers in descending order of the number of pages that the search server will find on each request. For the designation of the logical operation "or" in the query, the symbol is used - |, and for the logical operation "and" - &.
- baroque | classicism
- baroque | (Classicism & Modern)
- (Baroque & Ampir) | (Classicism & Modern)
- baroque | Ampir | Classicism | Modern
Consider in detail each request for the search server.
Option 1
"Baroque | Classicism "- on each page there must be information or Baroque, or classicism.
Option 2.
"Baroque | (Classicism & Modern) "- On each page there should be information or baroque, or about classicism and modernity immediately. On request "Classicism" there will be more results than on request "Classicism & Modern". "And" reduces the number of pages on request, the results will be found less than by previous request.
Option 3.
"(Baroque & Ampir) | (Classicism & Modern) "- On each page there should be information or Baroque and Ampira immediately, or about classicism and modernity immediately. Upon request "Baroque" there will be more results than at the request "Baroque & Ampir". Each "and" reduces the number of pages on request, the results will be found in less than the previous two.
Option 4.
"Baroque | Ampir | Classicism | Modern "- On each page there should be information or Baroque, or Ampira, or Classicism, or Modern. Since each "or" increases the number of pages on request, the results will be found most.
Thus, the correct answer is 4123. Request numbers are located in descending order of the number of pages that will find a search server for each request.
Answer: 4123.
An example of a task 4:
Searches for the search server. Place the queries numbers in ascending order of the number of pages that the search server will find for each request. To denote the logical operation "or" in the query, the symbol is used |, and for the logical operation "and" - &. In response, write down the four-digit number corresponding to the order of requests, for example, 2314.
- History & Russia & Monomach
- History & Russia | Monomakh)
- History & Russia & Vladimir & Monomach
- History | Russia | Monomakh
Consider in detail each request for the search server.
Option 1
"History & Russia & Monomakh" - on each page there must be information and about history, and about Russia, and about Monomakh. Each "and" reduces the number of pages on request.
Option 2.
"History & Russia | Monomakh)" - on each page there must be information about history and Russia or history and monomah. Since "and" reduces the number of pages on request, and "or" - increases, the results will be found more than on the first request.
Option 3.
"History & Russia & Vladimir & Monomakh" - on each page there must be information and about the history, and about Russia, and about Vladimir, and about Monomakh. Since "and" reduces the number of pages on request, the results will be found in the least.
Option 4.
"History | Russia | Monomakhs "- on each page there should be information or about history, or about Russia, or about Monomakh. Since each "or" increases the number of pages on request, the results will be found most.
Thus, the correct answer is 3124. Request numbers are located in an increase in the number of pages that will find a search server for each request.
ascending The number of pages that have found a search server for each request. Over all requests found a different number of pages.
To refer to the logical operation "or" in the query uses the symbol "|
Demonstration oGE version 2017 - Quest №11
Decision:
The more in the query "or", the more results gives the search server. The more in the query of operations "and", the less the results will be issued a search server. Thus, the answer is ADBC
In order ascending number of pages \u003d AdBc.
Answer: AdBc.
Searches for the search server. For each request, its code is specified - the corresponding letter from A to the city will write to the table of request codes from left to right in the order ascending The number of pages that have found a search server for each request. Over all requests found a different number of pages. To indicate a logical operation " OR»The query uses the symbol" | ", And for a logical operation" AND"- symbol" & ».
A: Marty | Donated | bear
B: Mozyshka & Donkey & Bear
Q: Martyshka & Donkey
G: (Martyshka & Donkey) | bear
Decision:
The more in the query "or", the more results gives the search server. The more in the query of operations "and", the less the results will be issued a search server. So the answer is BVG
Answer: BVGA
Searches for the search server. For each request, its code is specified - the corresponding letter from A to the city will write to the table of request codes from left to right in the order ascending | ", And for the logical operation" and "- the symbol" & ".
A: Frost | Sun | Day | Wonderful
B: (frost & sun) | Day
Q: Frost & Sun
G: Frost & Sun & Day & Wonderful
Decision:
The more in the query "or", the more results gives the search server. The more in the query of operations "and", the less the results will be issued a search server. So the answer of the GBB
Answer: GBBA
Searches for the search server. For each request, its code is specified - the corresponding letter from A to the city will write to the table of request codes from left to right in the order ascending The number of pages that have found a search server for each request. Over all requests found a different number of pages. To refer to the logical operation "or" in the query uses the symbol " | ", And for the logical operation" and "- the symbol" & ".
A: Rome & Paris & London
B: London | Rome
Q: Rome & London
G: Rome | Paris | London
Decision:
The more in the query "or", the more results gives the search server. The more in the query of operations "and", the less the results will be issued a search server. So Avbg's answer
Answer:
Searches for the search server. For each request, its code is specified - the corresponding letter from A to the city will write to the table of request codes from left to right in the order ascending The number of pages that have found a search server for each request. Over all requests found a different number of pages. To refer to the logical operation "or" in the query uses the symbol " | ", And for the logical operation" and "- the symbol" & ".
