Today, let's take a look at the lookup function in Excel. The basic syntax is Lookup (lookup_value, lookup_vector, result_vector ). It is easier to understand with examples:
Code
Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--> Hssfsheet sheet1 = Hssfworkbook. createsheet ( " Sheet1 " );Hssfrow row1 = Sheet1.createrow ( 0 );Row1.createcell ( 0
Two-point SearchThe binary lookup principle is simple:In an ordered array (this article discusses ascending, descending)Starting from the element in the middle of the array, if A[MID] is larger than the found element key, then find it in a[0] to a[mid-1] and vice versa in a[mid++] to a[a.lenth-1].From this point of view, the meaning of recursion is very strong ah, of course, can also be used in a non-recursive way, more efficient, meaning that binary
is huge at the same time (especially in the backbone router scenario), the number of routing caches will far exceed the number of routing table entries, and I wonder where the route cache is compared to the query advantage of the routing table. Would there be such an efficient route cache query algorithm? If so, why not apply directly to the longest prefix-matching routing table lookup? It is clear that the routing table
PrincipleBinary search also known as binary lookup, the advantages are less than the number of comparisons, Find Fast, the average performance is good, the disadvantage is that the unknown origin table is ordered table, and insert delete difficult. Therefore, the binary lookup method is suitable for an ordered list that does not change frequently and finds frequent. First, suppose that the elements in the t
Directory"SSH Advanced path" Step by step refactoring container implementation Spring Framework-starting with a simple container (eight)"SSH Advanced path" Step by step refactoring container to implement spring framework--two schemes to solve the "intrusive" management of containers for components--active lookup and control inversion (ix)"SSH Advanced path" Step by step refactoring container implementation Spring Framework-configuration file + Reflect
Binary Search Idea:When a static lookup table is represented by an ordered table, the lookup function can be implemented with a binary lookup.
Binary search finds the process by determining the interval of the unknown origin record, and then gradually narrowing the interval until it is found or cannot be found.
The time complexity of the 12-point
range of [f[k-2]-1], what is the basis?
While (Low
{
MID = low + f[k-1]-1;
if (Key
{
High = mid-1;
K = k-1;
}
Else if (key > A[mid])
{
Low = mid + 1;
K = k-2;
}
Else
{
if (mid
{
return mid;
}
Else
return n;
}
}
return-1;
}
Analytical:
The first thing to be clear: if the number of elements of an ordered table is n, and N is exactly (some Fibonacci number-1), i.e., n=f[k]-1, the Fibonacci
, uniform, no conflict, but prior knowledge of the distribution of keywords, suitable for small and continuous lookup table.2. Digital Analysis methodThe number of keywords, such as mobile phone number, may be the same as before, just a few different, extract a portion of the keyword to calculate the hash storage location. The keyword distribution is known beforehand and several bits are evenly distributed.3. The method of square takeThe keyword distr
This time to bring you the PHP array lookup function Usage summary, PHP array lookup function Use of the note what, the following is the actual case, take a look.
PHP looks in the array for the existence of the specified value, always using a foreach loop.There are better ways to use PHP's built-in three array functions to find out if a specified value exists in the array, and the three arrays are In_array
This topic is a bit large, and I have to strictly control the number of words, not like the "Proposition composition: in a IPv4 address tree to thoroughly understand the IP routing table of the various search process" so open. In fact, this composition is an extension of the interval finding section in the previous essay.The 1.IP packet classification is the core of the IP packet classification based on several fields of the IP packet protocol header, also called the matching domain, which divid
JAVA 5th course (sorting + Binary Search + lookup)
PS: algorithms are non-linguistic
Sort:
1. Extraction
2. Switch location
Import javax. swing. text. defaultEditorKit. insertBreakAction; import org. omg. cosNaming. namingContextExtPackage. addressHelper; public class Main {public static void main (String [] args) {// int [] B = new int [] {1, 2, 3, 4, 5 }; same as int B [] = {,}; // same as bubblesort (B); System. out. println ("Bubble sorting res
2016-08-12Content of the lesson:Process Control for the shellFile Lookup and compressionThe shell's Process control:Programming Languages:Sequential executionSelect ExecuteLoop execution (not spoken)Sequential execution:If statement:Single Branchif judgment condition; ThenBranch code with true conditionFiDual Branchif judgment condition; ThenBranch code with true conditionElseThe condition is a false branch codeFiMulti-Branchif CONDITION1; ThenIf-true
LocateNon-real-time, Fuzzy Lookup, lookup based on the system-wide file database.UpdateDB: Manually generating a file databaseAdvantages: Fast SpeedFindReal-time search, accurate search.Grammar:Find [Find path] [find standard] [processing action]Find path: Default to current directoryLookup criteria: Default to all files under the specified pathHandling actions: Default to showoptions [Find criteria]:-name
Locate non-real lookup, lookup is based on the system-wide file database,#updatedb, build the database manually, locate Find FastFind: Real-time precision, support for many search criteria, traverse all files in a given directory, slowFind Find path Lookup standard find standard find later processing operationFind the path: Default view current directoryFind stan
General statement: files on the server such as the vast starry sky, it is difficult to find a designated star. Fortunately, Linux provides us with two search commands. Search: Locate, findFirst, locate:The Locate command query file requires a database that relies on the system itself, and the database is routinely executed once a day. When we have this database, we can quickly search for files.
The locate relies on four components: the 1./usr/bin/updatedb #更新数据库文件, automatically runs 2.
Let i=$[$I +1]sum=$[$SUM + $I]Let sum+= $ILet i+=1 equivalent to let i++-=Let i-=1 equivalent to let i--grep, Egrep, Fgrep: Text lookupFile Lookup:Locate:Non-real-time, fuzzy matching, lookup is based on the system-wide file database;# UpdateDB, manually generate the file databaseFast speedFind:RealtimeAccurateSupport for many search criteriaTraverse all files in the specified directory to complete the lookup
/*** Order Lookup, Set Sentinel * to find an array: a[n] * To find elements: Key * * Method: * b[n+1], wherein, b[0] store key,b[1] to B[n] Element (A[0] to a[n-1) (B[n] from the back forward scan, if the search succeeds, return The subscript of the element in array B, starting at 1; If the lookup fails, return 0 * * The benefit of setting Sentinel: Avoid checking array subscript for cross-border after each
also means that when looking for keywords, you can use the binary, interpolation, Fibonacci and other ordered search algorithm.The improvement of the dense index is that it simplifies the large original data set, makes the large data set that cannot be loaded into memory, can load the memory at once, and can implement the sort of key loadline in memory, and each index entry can point to the original data record that it represents on the disk.The ability to take advantage of advanced
The Linux file lookup related commands generally involve two commands:
Locate
Find
LocateFormat:
Locate file name
Locate Regular expressions
DescriptionInstead of searching the file system, locate searches from a database. So the locate command searches very fast.However, the locate command cannot find the new file that was just created. The information for the new file is not saved to the database in real time. Wit
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.