Hes mein Code und ich kann nicht herausfinden, wo ich das Problem mit der Division durch Null bekomme.Mit einer Division durch Null in meinem Code
mreviewApp.cpp
const int SIZE = 80;
const char DELIMIT = '|';
void parseLine(const char line[], string& title, int& rating);
void stringTrim(char st[]);
void printMrList(std::vector <Mreview> mrList);
Mreview searchTitle(std::vector <Mreview> &mrList, string title);
int main()
{
ifstream fin;
fin.open("rating_list.txt");
if (fin.fail()) {
cerr << "Input file opening error.\n";
exit(1);
}
char line[SIZE];
string title;
int rating;
int lineCount = 0;
std::vector <Mreview> mrList;
/* Process one line at a time */
// Read the first line
fin.getline(line, SIZE);
stringTrim(line);
// Process loop
while (strlen(line) != 0) {
parseLine(line, title, rating);
lineCount++;
Mreview review = searchTitle(mrList, title);
review.addScore(rating);
// Read the next line
fin.getline(line, SIZE);
stringTrim(line);
}
cout << "** PROCESS DONE. There were " << mrList.size() << " movie titles. **\n\n";
printMrList(mrList);
// Close the input file before exit.
fin.close();
system("Pause");
return 0;
}
void parseLine(const char line[], string& title, int& rating)
{
char s[SIZE], r[SIZE];
const char *ptr, *temp1;
char *temp2;
ptr = strchr(line, DELIMIT);
if (ptr != NULL) {
// First grab the title string (until '|').
temp1 = line;
temp2 = s;
while (temp1 != ptr)
*temp2++ = *temp1++;
*temp2 = '\0';
stringTrim(s);
title = s;
// Second grab the rating number
temp1 = ptr+1;
temp2 = r;
while (*temp1 != '\0')
*temp2++ = *temp1++;
*temp2 = '\0';
stringTrim(r);
rating = atoi(r);
}
else {
title = "";
rating = 0;
}
}
void stringTrim(char st[])
{
char* ptr;
for (ptr = st; *ptr; ptr++) ;
for (ptr--; *ptr == ' ' && ptr >= st; ptr--) ;
ptr++;
*ptr = '\0';
for (ptr = st; *ptr && *ptr == ' '; ptr++) ;
if (*ptr && ptr != st) {
char* ptr2;
for (ptr2 = st; *ptr; *ptr2++ = *ptr++) ;
*ptr2 = '\0';
}
}
void printMrList(std::vector <Mreview> mrList)
{
std::vector<Mreview>::iterator itr;
for(itr = mrList.begin(); itr != mrList.end(); itr++) {
Mreview review = *(itr);
cout << review.getTitle() << "\t\t" << review.getTotalScore() << "\t\t" << review.aveRating() << endl;
}
}
Mreview searchTitle(std::vector <Mreview> &mrList, string title)
{
Mreview review (title);
std::vector<Mreview>::iterator itr;
for(itr = mrList.begin(); itr != mrList.end(); itr++) {
Mreview r2d2 = *(itr);
if(review.getTitle() == r2d2.getTitle())
return r2d2;
}
mrList.push_back(review);
return review;
}
mreview.cpp
Mreview::Mreview(string ttl)
: title(ttl), totalScore(0), numRatings(0) {}
Mreview::Mreview(string ttl, int score)
: title(ttl), totalScore(score), numRatings(1) {}
void Mreview::addScore(int score)
{
this->totalScore += score;
this->numRatings += 1;
}
double Mreview::aveRating() const
{
double rating = totalScore/numRatings;
return rating;
}
mreview.h
#ifndef MREVIEW_H
#define MREVIEW_H
#include <string>
using namespace std;
class Mreview
{
public:
Mreview(string ttl = "N/A");
Mreview(string ttl, int firstScore);
string getTitle() const { return title; }
int getTotalScore() const { return totalScore; }
int getNumRatings() const { return numRatings; }
void addScore(int score);
double aveRating() const;
private:
string title;
int totalScore;
int numRatings;
};
#endif
Mein Problem i Ich kann nicht herausfinden, was ich tun muss, um das Problem zu beheben. Ich habe die Kommentare gelesen und bin immer noch verwirrt.
Vielleicht wollen Sie die Syntax Ihrer Frage dort reparieren. –
Formatierung aufgeräumt ein wenig –
fragen Jon SKeet oder Scott Hanselman sie haben kein Problem damit –