程序应读取 2 个文件(author.dat 和 itation.dat)并将它们保存到地图和集合中; 首先它毫无问题地读取引文列表,然后它似乎正确地读取了作者,并且在遍历整个列表之后(author.dat)出现了浮点异常..无法弄清楚为什么
似乎发生在authorlist的构造函数内的author.cpp中
作者.cpp:
#include <fstream>
#include <iostream>
#include "authors.h"
using namespace std;
AuthorList::AuthorList(char *fileName) {
ifstream s (fileName);
int idTemp;
int nrTemp;
string nameTemp;
try {
while (true){
s >> idTemp >> nrTemp >> nameTemp;
cout << idTemp << " " << nrTemp << " " << nameTemp << " test_string";
authors.insert(std::make_pair(idTemp,Author(idTemp,nrTemp,nameTemp)));
if (!s){
cout << "IF-CLAUSE";
throw EOFException();
}
cout << "WHILE-LOOP_END" << endl;
}
} catch (EOFException){}
}
作者.h:
#ifndef CPP_AUTHORS_H
#define CPP_AUTHORS_H
#include <iostream>
#include <map>
#include <string>
#include "citations.h"
class Author {
public:
Author (int id, int nr, std::string name) :
articleID(id),
authorNR(nr),
authorName(name){}
int getArticleID() const {
return articleID;
}
std::string getAuthorName() const {
return authorName;
}
private:
int articleID;
int authorNR;
std::string authorName;
};
class AuthorList {
public:
AuthorList(char *fileName);
std::pair<std::multimap<int,Author>::const_iterator, std::multimap<int,Author>::const_iterator> findAuthors(int articleID) {
return authors.equal_range(articleID);
}
private:
std::multimap<int,Author> authors;
};
#endif //CPP_AUTHORS_H
程序.cpp:
#include <iostream>
#include <cstdlib>
#include "citations.h"
#include "authors.h"
#include "authorCitation.h"
using namespace std;
int main(int argc, char *argv[]){
CitationList *cl;
AuthorList *al;
//check if argv array has its supposed length
if (argc != 4){
cerr << "usage: programm article.dat citation.dat author.dat";
return EXIT_FAILURE;
}
//inserting citation.dat and author.dat in corresponding lists (article.dat not used)
cl = new CitationList(argv[2]);
al = new AuthorList(argv[3]);
try {
AuthorCitationList *acl;
acl->createAuthorCitationList(al,cl);
acl->printAuthorCitationList2File("authorcitation.dat");
} catch (EOFException){
cerr << "something went wrong while writing to file";
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
我敢打赌问题是由以下代码行引起的:
AuthorCitationList *acl;
acl->createAuthorCitationList(al,cl);
您正在使用未初始化的指针调用成员函数。我建议将第一行更改为:
AuthorCitationList *acl = new AuthorCitationList;
向构造函数添加任何必要的参数。
同时更改读取数据的循环。你有:
while (true){
s >> idTemp >> nrTemp >> nameTemp;
cout << idTemp << " " << nrTemp << " " << nameTemp << " test_string";
authors.insert(std::make_pair(idTemp,Author(idTemp,nrTemp,nameTemp)));
if (!s){
cout << "IF-CLAUSE";
throw EOFException();
}
cout << "WHILE-LOOP_END" << endl;
}
当您这样做时,您最终会在到达行尾后添加一次数据。另外,你似乎把最后一行放错了地方。在我看来,它应该在
while
循环之外。
您可以使用:
while (true){
s >> idTemp >> nrTemp >> nameTemp;
// Break out of the loop when reading the
// data is not successful.
if (!s){
cout << "IF-CLAUSE";
throw EOFException();
}
cout << idTemp << " " << nrTemp << " " << nameTemp << " test_string";
authors.insert(std::make_pair(idTemp,Author(idTemp,nrTemp,nameTemp)));
}
cout << "WHILE-LOOP_END" << endl;
您可以使用以下方法进一步简化:
while (s >> idTemp >> nrTemp >> nameTemp){
cout << idTemp << " " << nrTemp << " " << nameTemp << " test_string";
authors.insert(std::make_pair(idTemp,Author(idTemp,nrTemp,nameTemp)));
}
cout << "WHILE-LOOP_END" << endl;