comparison

问题 Is there a c# library/algorithm that compares 2 texts and displays what is different in them? 回答1: See Diff.Net: Diff.NET is a differencing utility I wrote in C#. It provides side-by-side differencing for files and directories. For files it also provides an overview diff and a line-to-line diff. And it can do a visual difference of binary files. 来源： https://stackoverflow.com/questions/1509771/text-comparison-difference-algorithm

问题 I've been learning Microsoft Access 2007 in a computer class at college and see that it's a very powerful database program... I realize that it might not be the same as a web server database, but I was thinking about switching to MSSQL. What are the biggest differences between MySQL and MSSQL? Does MS have any pros or cons that My might not have? How would one benefit me more than the other? 回答1: I have used extensively MS SQL Server. The main difference is MS SQL Server works only with

问题 How can I convert FILETIME to seconds? I need to compare two FILETIME objects.. I found this, but seems like it doesn't do the trick... ULARGE_INTEGER ull; ull.LowPart = lastWriteTimeLow1; ull.HighPart = lastWriteTimeHigh1; time_t lastModified = ull.QuadPart / 10000000ULL - 11644473600ULL; ULARGE_INTEGER xxx; xxx.LowPart = currentTimeLow1; xxx.HighPart = currentTimeHigh1; time_t current = xxx.QuadPart / 10000000ULL - 11644473600ULL; unsigned long SecondsInterval = current - lastModified; if

问题 I have an custom object which contains time period based information, for instance the attributes endCalYear, endMonth and periodLength which indicate the end of each period and its length. I would like to create an NSSortDescriptor based or other sorting method which combines these three attributes and allows sorting this object on all three keys at the same time. Example: EndCalYear endMonth periodLength (months) sortOrder 2012 6 6 1 2012 6 3 2 2012 3 3 3 2011 12 12 4 The sort algorithm

问题 Basically, if two strings would evaluate as the same in my database I'd also like to be able to check that at the application level. For example, if somebody enters "bjork" in a search field, I want PHP to be able to match that to the string "Björk" just as MySQL would. I'm guessing PHP has no direct equivalent to MySQL's collation options, and that the easiest thing to do would be to write a simple function that converts the strings, using strtolower() to make them uniformly lower-case and

问题 I am looking for performance efficient ways to compare two byte[] for equality. Sizes are above 1 MB, so the overhead for each array element should be minimized. I aim to beat the speeds of SequenceEqual or a hand-coded for-loop over every item, by avoiding the repetitive bound checks for both arrays. In the same way that Array.Copy could lead to fast memcpy , what will lead to a memcmp ? 回答1: If performance really matters then the fastest way to do it is by using the CRT library included

问题 I have the following problem. I have a set of elements that I can sort by a certain algorithm A . The sorting is good, but very expensive. There is also an algorithm B that can approximate the result of A. It is much faster, but the ordering will not be exactly the same. Taking the output of A as a 'golden standard' I need to get a meaningful estimate of the error resulting of the use of B on the same data. Could anyone please suggest any resource I could look at to solve my problem? Thanks

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: How to check whether 2 DirectoryInfo objects are pointing to the same directory? var dirUserSelected = new DirectoryInfo(Path.GetDirectoryName("SOME PATH")); var dirWorkingFolder = new DirectoryInfo(Path.GetDirectoryName("SAME PATH AS ABOVE")); if (dirUserSelected == dirWorkingFolder) { //this is skipped } if (dirUserSelected.Equals(dirWorkingFolder)) { //this is skipped } Whilst debugging, I can examine the

问题 I have some code I'm porting to a new platform, and it started giving me an error about comparing two enumerators from two different enumerator-lists. I'm confused why it's giving me an error about this. The enumeration specificers section of the C spec (6.7.2.2) states: The identifiers in an enumerator list are declared as constants that have type int and may appear wherever such are permitted. 127) An enumerator with = defines its enumeration constant as the value of the constant expression

问题 There are several places in BCL where one can make use of IEqualityComparer. Like Enumerable.Contains or Dictionary Constructor. I can provide my comparer if I'm not happy with the default one. Sometimes I want to know whether the collection contains that very object that I have reference to. Not the one that is considered "equal" in any other meaning. The question is: whether there exists standard equality comparer in the BCL that relies only on ReferenceEquals method? The one that I wrote