comparison

问题 I am trying to implement a custom binary search to run over a vector of dates. My binary search function is the following: template <typename RandomAccessIterator, typename Value, typename Comparer> inline int binary_search(RandomAccessIterator const first, RandomAccessIterator const last, Value const& value, Comparer comparer) { RandomAccessIterator it(std::lower_bound(first, last, value, comparer)); if (it == last || comparer(*it, value) || comparer(value, *it)) return distance(first,last);

问题 I have a working bit of code here where I am comparing the keys of six hashes together to find the ones that are common amongst all of them. I then combine the values from each hash into one value in a new hash. What I would like to do is make this scaleable. I would like to be able to easily go from comparing 3 hashes to 100 without having to go back into my code and altering it. Any thoughts on how I would achieve this? The rest of the code already works well for different input amounts,

问题 With a given array of file names, the most simpliest way to sort it by file extension is like this: Array.Sort(fileNames, (x, y) => Path.GetExtension(x).CompareTo(Path.GetExtension(y))); The problem is that on very long list (~800k) it takes very long to sort, while sorting by the whole file name is faster for a couple of seconds! Theoretical, there is a way to optimize it: instead of using Path.GetExtension() and compare the newly created extension-only-strings, we can provide a Comparison

问题 I want to compare 3 files together to see how much of the information in the files are the same. The file format is something like this: Chr11 447 . A C 74 . DP=22;AF1=1;CI95=1,1;DP4=0,0,9,8;MQ=15;FQ=-78 GT:PL:GQ 1/1:107,51,0:99 Chr10 449 . G C 35 . DP=26;AF1=0.5;CI95=0.5,0.5;DP4=5,0,7,8;MQ=20;FQ=11.3;PV4=0.055,0.0083,0.028,1 GT:PL:GQ 0/1:65,0,38:41 Chr12 517 . G A 222 . DP=122;AF1=1;CI95=1,1;DP4=0,0,77,40;MQ=23;FQ=-282 GT:PL:GQ 1/1:255,255,0:99 Chr10 761 . G A 41 . DP=93;AF1=0.5;CI95=0.5,0.5

问题 Suppose I have a class with several member variables: class MyClass{ std::string a; int b; SomeOtherClass c; // some stuff... public: // some other stuff... }; I want to define relational operators ( operator< , etc.) that first compare a , but if the a are equal, compare b , but if the b are equal, compare c . (We assume SomeOtherClass already has relational operators defined.) So I have something like bool operator==(MyClass param){ return (a == param.a) && (b == param.b) && (c == param.c);

问题 I want to compare two bmp files. I thought of two approaches: to compare the header as well as the information header of the two files convert the bmp file to binary and then do the above comparison But, I don't know how to start and which will be a better approach. I would be glad if someone could please help me! 回答1: I don't know on which platform you want to implement this, but here are some code snippets which could be useful: Compare two images with C# This is a snippet to compare 2

问题 I am trying to compare two string in C# but I cant find a way to get the result I need without building something myself. The strings: TestasdOne TestasdTwo The result: Testasd I tried linq but could not get it to work. I tried Google. Thanks in advance. 回答1: Here is the non-linq version which is more efficient, clear and readable public static string CommonPrefix(string a, string b) { if (a == null) throw new ArgumentNullException(nameof(a)); if (b == null) throw new ArgumentNullException

问题 I want to check whether the user input contains only digits or not. So, I use the following code: for(i = 0; argv[1][i] != NULL; i++) if(!isdigit(argv[1][i])) { printf("Error"); return -1; } It works well but I got this warning: warning: comparison between pointer and integer [enabled by default] since argv[1][i] is an Integer and NULL is a pointer. How can I avoid such warning? 回答1: NULL is not the same as the null-terminator character. You should use '\0' instead. 回答2: argv[1][i] is a char,

问题 I'm searching for the best (and fastest) way to compare VARCHAR2(50 BYTE) with CHAR(12 BYTE) . There are two databases, first contains a table1 with CHAR column (underline means space characters to fill CHAR length) ID VALUE 1 123-45___ 2 123-456__ 3 123-457__ second database (table2) contains VARCHAR2 without white space. ID VALUE 4 123-45 5 123-456 6 123-457 So, I want something like this SELECT table1.ID FROM table1 WHERE table1.VALUE = '123-45' 回答1: As the table1.value column is indexed,

问题 I have to compare a object with the raw properties of the same class. Meaning, i have to compare those: struct Identifier { string name; string email; } with the two strings name and email. I know i could just create a new Identifier instance for name and email and pass that into equals(). My application has to be very fast and resource-saving. I know that comparison via hashcode isn't a good way, because as explained here there are collisions. But collisions are okay for me, i just need it