whooops

[Techshrimp]

Hlo all!

I am in a bit of a jam with my C++ project for school. I am making a very simple program to randomly ask a 25 questions from a file storing any number of questions.Now i have two problems.

A)The program runs fine but the file it writes for scores seems currupt and doesnt reset to the values i have set as default.

B)Secondly I dunno how to make the file storing the various questions.

Plus I am having problems writing the class to a file.Can someone please take a look at the code and tell me all the things I am doing wrong? :)

#include <conio.h>
#include <string.h>
#include <fstream.h>
#include <stdlib.h>
#include<stdio.h>
 
    int noq=100;int qctr=0;
    int qnchk[24]={-1,-1,-1,-1,-1,1,-1,-1,-1,-1,1,-1,-1,-1,-1,1,-1,-1,-1,-1,1,-1,-1,-1};
    void quiz(char name[]);
    int qrand(void);//To randomize questions
    void ready(void);
    void reset(void);
    struct player{char name[];
              int score;
             }player;
    class qs
        {int abit;
         char q[],a1[],a2[],a3[],a4[]; //Declare variables for  question and answers
         public:
         void disp(void);//To display questions
         void r_in(int x);//To read in values of answers,questions and flags
         void check(int ch);//To check answer
         int qno;
        }Qstn;
    int offset=sizeof(Qstn);
    void qs::r_in(int x)
        {
          fstream file;
          file.open("Gdata.txt",ios::out);
          file.seekg((offset*x),ios::beg);
          file.read((char*) &Qstn,sizeof(Qstn));
          file.getline(q,"\t");
          return;
        }
 
    int qrand(void)
        {int a=-1,b=0;
         do
         {rerun:randomize();
          a=rand()%noq+1;
          for (int ctr=0;ctr<24;ctr++) { if(qnchk[ctr]==a) {b=1;}}
          if (b==1)
          goto rerun;
         }while(a>noq || a<0);
         return(a);
        }
 
    void qs::check(int ch)
        {clrscr();
         if (ch==abit)
         {cout<<"\n\n\t\tRight Answer!\n";
          player.score+=10;
         }
          else {cout<<"\n\n\t\tWrong Answer!\n";}
          return;
        }
 
    void qs::disp(void)
        {cout<<"\n\nQ."<<qctr<<") ";
         puts(q);
         cout<<"\n\n<1> ";
         puts(a1);cout<<"\n\t<2> ";puts(a2);
         cout<<"\n<3> ";
         puts(a3);cout<<"\n\t<4> ";puts(a4);
         cout<<"\n\nEnter Your Choice (1,2,3 or 4) ";
         return;
        }
 
    void quiz(char name[])
        {clrscr();int qvar,ch;struct player temp; player.score=0;
         cout<<"\t\t\tQUIZMASTER\n\t\t\t----------\n\t\tSCORE: "<<player.score;
         cout<<"\n\nReady ";
         puts(name);
         cout<<" (Y/N)?";
         char choice;    cin>>choice;
         if (choice=='N' || choice=='n') {return;}
         for (int i=0;i<25;i++)
         {ch=0;
          qvar=qrand();
          Qstn.r_in(qvar);
          qnchk[i]=Qstn.qno;
          qctr=i+1;Qstn.disp();
          cin>>ch;
          Qstn.check(ch);
          cout<<"\nNext Question (Y/N) ? ";
          cin>>choice; if(choice=='N' || choice=='n') {cout<<"\nExiting...\n";break;}
         }
         fstream f1,f2; f1.open("Player.rec",ios::app|ios::out|ios::in);f2.open("temp.dat",ios::out|ios::trunc);i=1;
         if(!f1)
         {
          cout<<"\nERROR : No file exists!\n";
          return;
         }
         while(!f1.eof() && i<10)
         {
          f1.read((char*) &temp,sizeof(temp));
          if(player.score<temp.score)
          {
           f2.write((char*)&temp,sizeof(temp)); i++;
          }
          if(player.score==temp.score)
           {
            f2.write((char*)&temp,sizeof(temp));
            f2.write((char*)&player,sizeof(player));
            i+=2;
           }
          if(player.score>temp.score)
           {
            f2.write((char*)&player,sizeof(player));
            i++;
           }
         }
          f1.close(); f2.close();
          remove("Player.rec"); rename("temp.dat","Player.rec");
          clrscr();
          if(i<=10)
          {cout<<"\n\n\t\tHI-SCORE!!!";
          }
          clrscr();
          return;
        }
 
 

[Techshrimp]

contd...

void main()
        {
         char opt;
         ready();
         while(opt!='E' || opt!='e')
         {clrscr();char xb=' ';
          gotoxy(30,7);    cprintf("QUIZ MASTER");
          gotoxy(29,8);    cprintf("-------------");
          gotoxy(31,10);    cprintf("Main Menu");
          gotoxy(30,11);    cprintf("-----------");
          gotoxy(34,14);    cprintf("New");
          gotoxy(32,16);    cprintf("HISCORE");
          gotoxy(29,18);    cprintf("Instructions");
          gotoxy(32,20);    cprintf("E X I T");
          gotoxy(0,17);
          cout<<"\n\n\tSelect an option (N for new game,H for hiscores,I for\n";
          cout<<"\tinstructions or E to exit ";
          cin>>opt;
          if(opt=='N' || opt=='n')
           {
            cout<<"\n\t\tEnter player name ";
            gets(player.name);
            quiz(player.name);
            opt=' ';continue;
           }
          if(opt=='H' || opt=='h')
           {clrscr();    opt=' ';
            struct player t1;
            gotoxy(32,10);    cprintf("~HI SCORES~");
            gotoxy(31,11);    cprintf("-------------");
            gotoxy(0,15);
            ifstream f1;
            f1.open("Player.rec",ios::in|ios::nocreate);
            f1.seekg(0);cout<<"\tRank\tName\tScore\n";
            for(int i=0;i<10;i++)
            {
             f1.read((char *) &t1,sizeof(t1));
             cout<<"\t"<<i<<"\t"<<t1.name<<"\t"<<t1.score<<endl;
            }
            f1.close();
            cout<<"\n\n\tPress R to reset hiscores or any other key to go back :";
            cin>>xb;
            if(xb=='R' || xb=='r')
             {reset();
             }
            continue;
           }
          if(opt=='I' || opt=='i')
           {
            clrscr();
            cout<<"\n\n\t\tINSTRUCTIONS\n\n\n";
            cout<<"\tAnswer the questions by entering the number of the option you think\n";
            cout<<"\tis correct.\n\n\n\nPress any key to return to main menu... ";
            opt=' ';cin>>xb;
            continue;
           }
          if(opt=='E' || opt=='e')
           {clrscr();
            cout<<"\n\n\n\n\tHave a nice day!";
            break;
           }
         }
         getch();
        }
 
    void ready(void)
        {
         fstream f1;
         f1.open("Player.rec",ios::out|ios::nocreate);
         if(f1.fail())
         {f1.close(); f1.open("Player.rec",ios::in);
          strcpy(player.name,"H4x0r");player.score=1;
          for(int i=0;i<10;i++)
           {f1.write((char*)&player,sizeof(player));
            player.score*=i;
           }
         strcpy(player.name,"");player.score=0;
         f1.close(); f1.open("Gdata.txt",ios::out|ios::in|ios::nocreate);f1.close();
         }
         return;
        }
 
    void reset(void)
        {clrscr();
         remove("Player.rec");
         ready();
         cout<<"Hiscores cleared!";
         return;
        }

[willakawill]

Hi. That's a lot of code to work through.
In general:
If you want to save data like this you need to know the size of the record to write and read accurately so you need to write a long value representing the size of your struct. This is because you have a variable length string and you don't know how many bytes to read from the file.

You could also change to using fixed length strings:

struct player{
   char name[50];
   int score;
};

This makes life so much easier saving and writing to a binary file
Incidentally, I would refrain from giving the instance of my player struct the same name as the typedef. Not the best practise.

With regard to the questions. The same thing applies. I assume you will need to store an answer:

struct question {
   char question[100];
   char answer[100];
   int CorrectChoice;
};

When saving or reading your array of questions you will need to store a long value at the beginning of the file to let you know how many questions there are so you can set the array to the correct length.