/* compiler used:                                             */
/* simple application to generate basic arithmetic operations */
/* March/3rd/2006, John Bofarull                              */

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<time.h>

#define RAND__MAX 4294967295

#define OPS 40                      /* how many operations per file */

/* poke about these 8  constants to harden or soften tests */
#define SDL 4                       /* sums level */
#define RDL 4                       /* differences level */
#define PDL_1 27                    /* products level */
#define PDL_2 153
#define PDL 37768
#define DDL_1 398                   /* division thresholds */
#define DDL_2 12

void insert_txt(char *, char *);

void main()
{FILE *fp;
 char file_name[12];
 char s_txt[]=".txt";
 int j=0;
 unsigned long int k,q,m,n;
 unsigned long int g;
 char c;

/* which operation */

for(;;)
 {randomize();
  printf("\nAdd/Sub/Prod/Div  (A/S/P/D)  (Q=quit program): ");
  c=getche();
  if (c=='a') c='A';
  if (c=='s') c='S';
  if (c=='p') c='P';
  if (c=='d') c='D';
  if ((c=='q')||(c=='Q')) c=0x1b;
  j=0;

switch(c)
{
{case'A':
 c='\0';
 printf("\nWhich file to write sums in (8 chars max/.txt by default)?");
 scanf("%s",file_name);
 insert_txt(file_name,s_txt);           /* no need to type .txt at the end of file name */
 if((fp=fopen(file_name,"w"))==NULL) printf("\nFile not found");
 while(j<OPS)
  {fprintf(fp,"\n%3d .- ",j+1);
   k=rand();q=rand();m=rand();n=rand();
                            /* avoiding operations with 0 or 1 */
   while((k==0)||(k==1)||(k==10)||(k==100)||(k==1000)) k=rand();
   while((q==k)||(q==0)||(q==1)||(q==10)||(q==100)||(q==1000)) q=rand();
   while((m==k)||(m==q)||(m==0)||(m==1)||(m==10)||(m==100)||(m==1000)) m=rand();
   while((n==k)||(n==q)||(n==m)||(n==0)||(n==1)||(n==10)||(n==100)||(n==1000)) n=rand();
   k=k/SDL;q=q/SDL;m=m/SDL;n=n/SDL;         /* corrections */
   g=k+q+m+n;                       /* operation */
   fprintf(fp,"%5u + ",k);
   fprintf(fp,"%5u + ",q);
   fprintf(fp,"%5u + ",m);
   fprintf(fp,"%5u",n);
   fprintf(fp,"  =               %15u ",g);     /* 15 blank chars to the right */
   j++; }
 fclose(fp);
 break;}                        /* case Addition over */

{case 'S':
 c='\0';
 printf("\nWhich file to write substractions in (8 chars max/.txt by default)?");
 scanf("%s",file_name);
 insert_txt(file_name,s_txt);               /* no need to write .txt */
 if((fp=fopen(file_name,"w"))==NULL) printf("\nFile not found");
 while(j<OPS)
  {fprintf(fp,"\n%3d .- ",j+1);
   k=rand();q=rand();
   while((k==0)||(k==1)||(k==10)||(k==100)||(k==1000)) k=rand();
   while((q==k)||(q==0)||(q==1)||(q==10)||(q==100)||(q==1000)) q=rand();
   k=k/SDL;q=q/RDL;
   if(k>q)
    {g=k-q;
     fprintf(fp,"%5u - ",k);
     fprintf(fp,"%5u",q);
     fprintf(fp,"  =               %6u",g); }       /* 15 blank chars to the right */
     else
     {g=q-k;
      fprintf(fp,"%5u - ",q);
      fprintf(fp,"%5u",k);
      fprintf(fp,"  =               %6u",g); }
   j++;}
 fclose(fp);
 break;  }                          /* case Substraction over */

{case 'P':
 c='\0';
 printf("\nWhich file to write divisions in (8 chars max/.txt by default)?");
 scanf("%s",file_name);
 insert_txt(file_name,s_txt);               /* no need to write .txt */
 if((fp=fopen(file_name,"w"))==NULL) printf("\nFile not found");
 while(j<OPS)
  {fprintf(fp,"\n%3d .- ",j+1);
   k=rand();q=rand();
   k=k/PDL_1;q=q/PDL_2;

   while((k==0)||(k==1)||(k==10)||(k==100)||(k==1000)) k=rand();
   while((q==k)||(q==0)||(q==1)||(q==10)||(q==100)||(q==1000)) q=rand();

   g=k*q;
   fprintf(fp,"%5u  *  ",k);
   fprintf(fp,"%5u",q);
   fprintf(fp,"  =               %15u",g);
   j++;}
 fclose(fp);
 break;}                        /* case Product over */

{case 'D':
 c='\0';
 printf("\nWhich file to write divisions in (8 chars max/.txt by default)?");
 scanf("%s",file_name);
 insert_txt(file_name,s_txt);               /* no need to write .txt */
 if((fp=fopen(file_name,"w"))==NULL) printf("\nFile not found");
 while(j<OPS)
  {fprintf(fp,"\n%3d .- ",j+1);
   k=rand();q=rand();
   k=k/PDL_1;q=q/PDL_2;

   while((k==0)||(k==1)||(k==10)||(k==100)||(k==1000)) k=rand();
   while((q==k)||(q==0)||(q==1)||(q==10)||(q==100)||(q==1000)) q=rand();

   while((k*q)>=65333)
    {k=rand();q=rand();
     k=k/PDL_1;q=q/PDL_2;

     while((k==0)||(k==1)||(k==10)||(k==100)||(k==1000)) k=rand();
     while((q==k)||(q==0)||(q==1)||(q==10)||(q==100)||(q==1000)) q=rand();}

     g=k*q;
     fprintf(fp,"%5u / ",g);
     fprintf(fp,"%5u",q);
     fprintf(fp,"  =               %5u",k);
 j++;}
 fclose(fp);
 break;}                            /* case Division over */

case 0x1b:
{puts("\nEnd of program"); exit(0);}
default: puts("\nOption not Valid");

   }    /* switch terminated */
  } /* for terminated */
 } /* main terminated */


/****************** Functions Definitions *********************/

void insert_txt(char *s1, char *s2) /* adding .txt extension to result file names */
{while (*s1) s1++;
 while (*s1++=*s2++);}

I'm impressed. That's a beautiful example of how not to program in C.

:))
I like your comment. Honesty is a precious asset.
Bofarull

>I like your comment. Honesty is a precious asset.
I'm glad you approve. You'll get nothing but honesty from me. ;) Anyway, did you have a question that you needed help with?

Well said!

Faced with the choice of code and no question vs. a question with no code, I prefer the former... ;)

There was no intention to ask a single question about this specific code.

I am aware of shorter ways to do the same, I am aware that I am not as skilled as most around in this forum, and the code is here just for any other beginner who would like to use it.

I have plenty of questions but I ask them at the right time.
I am also looking for C literature resources.

I'm not the kind of guy hanging around others to learn.

Only when jammed at a given point I will use artillery and ask you, hoggy doggy?

Nevertherless I sincerely appreciate every single comment here appended.

bofarull :mrgreen:

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