Lost on columns

[Extropian]

I have to put some output in columns, but I don't even know where to get started. I just wondered if anybody could tell me what I should read about or how I may I get started, that would be a really big help, thanks.
Basically, its just numbers but instead of the output being something like:
1
2
3
4
5
and so on, it would look like:

1 2 3 5

6 7 8 9... and so on


thanks,
Extro

[kermit]

Perhaps you could post the source code for the attempt you have made. Then we can help. If you need a hint to get started, think about how you might use some sort of a loop, and the % (modulus) operator to generate the output you are looking for.

~/

[Extropian]

This is the code:

include <stdio.h>

int main (){
    int	open=0, skip;
    int	cnt = 0, skipped=0;
       
    printf ("How many mail boxes does he skip?\n");
    scanf("%d" , &skip);

    while (cnt < 150){
        cnt++;
        if (cnt % skip == 0){
            open++;
            printf("%d = closed\n", cnt);
        }else{
            skipped++;
            printf("%d = open\n", cnt);
        }
    }
    printf("Opened a total of %d boxes\nSkipped a total of %d boxes\n", open, skipped);

    return 0;
}

But right now it outputs it:

1 = open

2 = open
3= open
4-closed

etc... depnding on the input
but I need it to display it like:

1 = open 2 = open 3 = open 4 = open

5 = closed 6 = closed 7 = open

and so on to 150.

Most of the instructions I have found so far on how to do this are hard to understand.
Thanks,
Extro

[Hammer]

The \n in those printf() statements will cause newline character to be written. As you're doing it in both printf()s, you'll be starting a newline every time.
Use the modulos operator to determine when to start a newline, and output a \n then only.

[Extropian]

You mean something like this?

#include <stdio.h>

int main (){
    int	open=0, skip;		
    int	cnt = 0, skipped=0;        
    printf ("How many mail boxes does he skip?\n");
    scanf("%d" , &skip);

    while (cnt < 150){
        cnt++;
        if (cnt % skip == 0){
            open++;
            printf("%5d\n = closed\n", cnt);
        }else{
            skipped++;
            printf("%5d\n = open\n", cnt);
        }
    }
        return 0;
}

[kermit]

After compiling your (above) code, did you find it did what you wanted? What Hammer suggested will work for you - get rid of the newlines, and use the modulus operator to determine when you need to insert the newline - from what I understand, you want a newline after every fourth column. So you ought to be checking your code something like this:

some_var % 4

edit::

You are iterating through your loop, in this case, 150 times - every time you go through the loop, increment a counter, and every fourth time, insert a newline.

~/

[Extropian]

So far, it isnt working, although I understand what your saying it doesnt seem to wanna work
Mostly I'm having a hard time figuring out where the modulus should go
Thanks,
Extro

[kermit]

So far, it isnt working, although I understand what your saying it doesnt seem to wanna work
Mostly I'm having a hard time figuring out where the modulus should go
Thanks,
Extro

Perhaps you could do a simpler program, which prints out the numbers 1 to 20 in four columns - if you can get that to work, you will likely see how to modify this program to work the way you want it to.

~/

[Extropian]

Im sorry but I wouldnt know how? where does the mod operator go to create 4 columns? I dont mean to bother but Im really stuck

[Raptor007]

Try something like this:

// Loop through all values in the array.
for (i = 0; i < size; i++) {

    // Print the current value.
    printf ("%i", array[i]);

    // If the current index is the end of a row (of size width), print a newline.
    if (i % width == width - 1)
        printf ("\n");

    // Otherwise print a tab character to make spacing clean.
    else
        printf ("\t");
}

[Extropian]

can somebody attempt this for me a little? I hate asking but I'm hoping if I see it maybe I'll understand because this is just not sinking into the my little brain lol
Thanks.

[Dave_Sinkula]

Well, methods have already been suggested, but I'll try this.

#include <stdio.h>

int main(void)
{
   int array[] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18};
   size_t i, size = 4;
   for ( i = 0; i < sizeof array / sizeof *array; ++i )
   {
      printf("%3d", array[i]);
      if ( i % size == size - 1 )
      {
         putchar('\n');
      }
      else
      {
         putchar(' ');
      }
   }
   putchar('\n');
   return 0;
}

/* my output
  1   2   3   4
  5   6   7   8
  9  10  11  12
 13  14  15  16
 17  18 
*/

[Extropian]

Thanks, I'm really kind of a see and learn guy. I had a hunch it was an array but couldn't get it to work.
Thanks a bunch,
Extro

[Raptor007]

It doesn't have to be an array, I just figured you had an array of values.

Here it is with just plain sequential integers:

// Loop through all values in the array.
for (i = 0; i < max; i++) {

    // Print the current value.
    printf ("%i", i);

    // If the current index is the end of a row (of size width), print a newline.
    if (i % width == width - 1)
        printf ("\n");

    // Otherwise print a tab character to make spacing clean.
    else
        printf ("\t");
}

[Dave_Sinkula]

I had a hunch it was an array but couldn't get it to work.

It need not be.

#include <stdio.h>

int main(void)
{
   static const char filename[] = "file.txt";
   FILE *file = fopen(filename, "r");
   if (file)
   {
      int value;
      size_t i = 0, size = 4;
      while ( fscanf(file, "%d", &value) == 1 )
      {
         printf("%3d", value);
         if ( i % size == size - 1 )
         {
            putchar('\n');
         }
         else
         {
            putchar(' ');
         }
         ++i;
      }
      putchar('\n');
   }
   return 0;
}

/* file.txt
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 
*/

/* my output
  1   2   3   4
  5   6   7   8
  9  10  11  12
 13  14  15  16
 17  18 
*/