c++ - Merging two sorted vectors in one sorted vector -

-

background: general goal take 2 sorted files strings separated white space, , bring them in 1 sorted file.

current goal, see if can use merge function or similar function combine 2 sorted vectors.

i using http://www.cplusplus.com/reference/algorithm/merge/, guide use of function merge. however, error "no matching function call 'merge'".

i'm not sure if merge function wanting strings, trying use see if does. 

#include <iostream> #include <fstream>   #include <vector> #include <algorithm>    // std::merge, std::sort #include <string> using namespace std;  ifstream r_data_file(const string oname) {     ifstream ist {oname};     if (!ist) {         string error = "cannot open " + oname;         throw runtime_error(error);     }     return ist; }  void get_words(ifstream& ist, vector<string>& po) {     (string p; ist >> p;) {         po.push_back(p);     } }  int main () {     vector<string> file1;     vector<string> file2;     ifstream ist = r_data_file("wordlist_1.txt");     get_words(ist, file1);     ifstream ist_2 = r_data_file("wordlist_2.txt");     get_words(ist_2, file2);     vector<string> file_1n2(file1.size()+file2.size());     merge(file1, file1.end(), file2, file2.end(), file_1n2);  }

i appreciate thoughts, cheers!

you cannot use file1, file2 , file_1n2 simple pointers(maybe confusion comes because use plain arrays in way). here merge uses stl iterators, not pointer. fix problem, use:

merge(file1.begin(), file1.end(), file2.begin(), file2.end(), file_1n2.begin());

Comments

Post a Comment

Popular posts from this blog

c# - How Configure Devart dotConnect for SQLite Code First? -

-
can configure following sample code ? when run following code, error : no entity framework provider found ado.net provider invariant name 'devart.data.sqlite' setting in machine.config <system.data> <dbproviderfactories> <add name="dotconnect sqlite" invariant="devart.data.sqlite" description="devart dotconnect sqlite" type="devart.data.sqlite.sqliteproviderfactory, devart.data.sqlite, version=4.6.287.0, culture=neutral, publickeytoken=09af7300eec23701" /> </dbproviderfactories> </system.data> after add below block code in app.config <?xml version="1.0"?> <configuration>   <configsections> <!-- more information on entity framework configuration, visit http://go.microsoft.com/fwlink/?linkid=237468 --> <section name="entityframework" type="system.data.entity.internal.configfile.entityframeworksection, entit...
Read more

java - Copying object fields -

-
what best way of copying classes when need have 2 independent variables? have simple class: public class myclass { boolean = false; string b= "not empty"; } do need make method : assign(myclass data ) { a= data.a; b= data.b; } is there automatic method copy (duplicate) objects in java? do need make method : pretty close. instead of making method, should make constructor. such constructors called copy constructor , , create them this: myclass(myclass data) { = data.a; b = data.b; } and create copy of instance, use constructor this: myclass obj1 = new myclass(); myclass obj2 = new myclass(obj1); copy constructor can tedious : using copy constructor create deep-copy can tedious, when class has mutable fields. in case, assignment create copy of reference, , not object itself. have create copy of fields (if want deep copy). can go recursive. a better way create deep copy serialize , deserialize object. why not use clone()? ...
Read more

c++ - Clear the memory after returning a vector in a function -

-
i have function processes , stores lot of data in , returns results vector of class. amount of data stored in function tremendous , want clear storage memory of function after finished job. necessary (does function automatically clear memory) or should clear memory function? update: vector<customers> process(char* const *filename, vector<int> id) { vector<customers> list_of_customers; (perform actions) return list_of_customers; } variables defined locally within function automatically released @ end of function scope. destructors objects called, should free memory allocated objects (if objects coded correctly). example of such object std::vector . anything you've allocated new must have corresponding delete release storage. try avoid doing own allocation , use raii instead, i.e. containers or smart pointers.
Read more