C++ Address Book
 

Hi, I have to write an address book using structs for a class. I have 90% of the code done, but I am having trouble ordering it. It is supposed to read in 10 entries from a file and then sort them by last name. All the information also has to be swapped. I am using Microsoft VC++ 6. I would appreciate any input on what might be wrong with this program. Thanks for the help. :)

 #include <iostream>

#include <string>

#include <fstream>

#include <algorithm>

using namespace std;

struct student

{

 string first_name;

 string last_name;

 string phone_number;

 string age;

 int month;

 int day;

 int year;

};

student log[100];

//double uslessfunction1(student log[].first_name,student log[].last_name,student log[].phone_number);

void uslessfunction1(student log[],ifstream infile,int x);

//double uslessfunction2(student log[].age,student log[].month,student log[].day,student log[].year);

void uslessfunction2(student log[],ifstream infile,int x);

void main()

{

 double num=0,x=0,counter=0;

 ifstream infile;

 ofstream outfile;

 infile.open("database.txt");

 outfile.open("output.txt");

 while(!infile.eof()){

 { counter=counter+1;

 

//  uslessfunction1(log[].first_name,log[].last_name,log[].phone_number);

  uslessfunction1(log[x],infile,x);

//  uslessfunction2(log[].age,log[].month,log[].day,log[].year);

  uslessfunction2(log[x],infile,x);

  x=x+1;

 }

 

 for (x=0;x<counter;x++)

  sort(log[x].first_name,log[x].first_name,10);

 for (x=0;x<counter;x++)

  outfile<<log[x].last_name<<", "<<log.first_name<<endl<<log[x].phone_number<<endl<<log[x].month<<"/"<<log[x].day<<"/"<<log[x].year<<endl;

 

}

//double uslessfunction1(student log[].first_name,student log[].last_name,student log[].phone_number)

void uslessfunction1(student log[],ifstream infile,int x)

{

 infile>>log[x].first_name;

 infile>>log[x].last_name;

 infile>>log[x].phone_number;

}

//double uslessfunction2(student log[].age,student log[].month,student log[].day,student log[].year)

void uslessfunction2(student log[],ifstream infile,int x)

{

 infile>>log[x].age;

 infile>>log[x].month,log[x].day,log[x].year;

}

Re: C++ Address Book
 

Just incase anyone is having the same problem, I got it after much work. I guess my inputs on the date were wrong, causing traumatic memory problems :)

If anyone is interested in the code, here it is

#include <iostream>

#include <string>

#include <fstream>

#include <algorithm>

using namespace std;

struct student

{

 string first_name;

 string last_name;

 string phone_number;

 string age;

 string month;

 string day;

 string year;

};

student log[100];

void main()

{

 int num=0,x=0,counter=0,y=0;

 student temp;

 ifstream infile;

 ofstream outfile;

 infile.open("database.txt");

 outfile.open("output.txt");

 while(!infile.eof())

 { counter=counter+1;

 

  infile>>log[x].first_name;

  infile>>log[x].last_name;

  infile>>log[x].phone_number;

  infile>>log[x].age;

  infile>>log[x].month;

  infile>>log[x].day;

  infile>>log[x].year;

  x=x+1;

 }

 for (x=0;x<counter;x++){

  for(y=x+1;y<10;y++){

   if (log[x].last_name > log[y].last_name){

        temp = log[x];

        log[x] = log[y];

        log[y] = temp;

   }

  }   

 }

 for (x=0;x<counter;x++)

  outfile<<log[x].last_name<<", "<<log[x].first_name<<endl<<log[x].phone_number<<endl<<log[x].month<<"/"<<log[x].day<<"/"<<log[x].year<<endl<<endl;

}

Re: C++ Address Book
 

just wanted to let you know that you've re-discovered the 'bubble sort' algorithm. The code looks fine except that you should use 'x += 1' instead of 'x = x + 1' -- it's faster. you may not see much of a difference in a loop of that many iterations or with numbers, but it'll really help with strings and loops with more iterations. Besides, it's faster to type! Keep up the good work

Re: C++ Address Book
 

it is faster to type but there's no difference in the code generated, test it and see for yourself.

Re: C++ Address Book
 

According to this book I have, 'C++ for Game Programmers' published by Charles River Media, it says that it's a lot faster when dealing with CString operations, I will go back to it and make sure, but I'm pretty sure now. I haven't tested it, but I was taking the book's word. But I appreciate your comment; that makes me investigate!!

Re: C++ Address Book
 

ok, if you're talking about something high level like that it may be true, but for say some simple integer x it makes no difference in the generated asm. :)