C array print layout

Creamy Goodness

hey i have a simple C program that i want to ask the user how many array elements they want from the keyboard, then randomly put values into each array element, then print the values of the array in groups of 5.

example output would be:

enter in amount of array elements: 7

01 02 03 04 05

06 07

enter in amount of array elements: 10

01 02 03 04 05

06 07 08 09 10

enter in amount of array elements: 12
 
01 02 03 04 05
 
06 07 08 09 10

11 12

i'd like to have the amount of elements that are on a row taken in from the keyboard so the user has complete control over how many elements and how many per row are displayed.

here's what i've got at the moment (not all code is here like #includes etc that aren't relevant to the problem).

int num_elements = 0;
int num_elements_row = 0;

printf("please enter the amount of elements you want: ");
scanf("%d", &num_elements);

printf("\nplease enter the amount of elements you want on each row: ");
scanf("%d", &num_elements_row);

int array[num_elements];

int i = 0;

for(i = 0 ; i < num_elements; i++)
{
     array[i] = rand()%1000;
}

//now to attempt printing out the elements in their rows.
for(i = 0 ; i < num_elements; i++)
{
    printf("%d ", array[i]);
}

now the last for loop will print out the elements all on one line no problem but i'm having difficulty visualising how i'd get it to skip to a new line after the num_elements_row limit is hit.

FruitLover

Use the counter variable in the output loop. If it (plus 1) is cleanly divisible by num_elements_row, then bump.

Webmonkey

Continuing from what FruitLover said...

Haven't tested anything but could use modulo function:

//now to attempt printing out the elements in their rows.
for(i = 0 ; i < num_elements; i++)
{
    printf("%d ", array[i]);
    if ((i +1) % num_elements_row == 0)
      printf("\n ");
}

Creamy Goodness

thanks guys, i forgot about the modulus operator .

ya should have seen some of the long winded code involving a counter here, a counter there, a counter everywhere to try and solve this.

mark renton

While im in here - cant remember how to search text file for char ' - whats the syntax?? Below for colon but does complier accept ''' ??

if (a_single_character == ':'){
colon = colon + 1;
a_single_character = (char)fgetc(fp);

Webmonkey

You have to escape it, ie. \'.

So

if (a_single_character == '\'')
{ ...

mark renton

Youre a Gentleman - thanks

LARDO

u could have a 2 dimensional array!

Creamy Goodness

another problem but unrelated and i don't want to start another thread.

lets say i have an array of size 20.

int array[20];

to which i insert a random number into by the following.

for(i = 0 ; i < 20 ; i++)
          array[i] = rand()%100;

which will put a random number into each element. this works fine, but there are certain numbers that may pop up for example 0, 1, 2, 3 that i do not want to be put in the array. but i need all elements filled with a number between 4-100 and no duplicate values if possible

Webmonkey

Creamy Goodness wrote: »

another problem but unrelated and i don't want to start another thread.

lets say i have an array of size 20.

int array[20];

to which i insert a random number into by the following.

for(i = 0 ; i < 20 ; i++)
          array[i] = rand()%100;

which will put a random number into each element. this works fine, but there are certain numbers that may pop up for example 0, 1, 2, 3 that i do not want to be put in the array. but i need all elements filled with a number between 4-100.

for(i = 0 ; i < 20 ; i++)
          array[i] = rand()%96 + 4;

MOH

Creamy Goodness wrote: »

which will put a random number into each element. this works fine, but there are certain numbers that may pop up for example 0, 1, 2, 3 that i do not want to be put in the array. but i need all elements filled with a number between 4-100.

rand()%96 + 4 will give you 4 to 99
or ran()%97 + 4 for 4 to 100, inclusive

Webmonkey

MOH wrote: »

rand()%96 + 4 will give you 4 to 99
or ran()%97 + 4 for 4 to 100, inclusive

Sorry, typo - MOH is correct.

(rand()%(maximum-minimum))+minimum

Creamy Goodness

thanks guys :pac: