trying to implement this code in c

Hi,

I am trying to implement this PHP code in C:

Code:

    function showCombinations($string, $traits, $i)
    {
        if ($i >= count($traits))
            echo trim($string) . "\n";
        else
        {
            foreach ($traits[$i] as $trait)
                showCombinations("$string $trait", $traits, $i + 1);
        }
    }

    $traits = array
    (
        array('Happy', 'Sad', 'Angry', 'Hopeful'),
        array('Outgoing', 'Introverted'),
        array('Tall', 'Short', 'Medium'),
        array('Handsome', 'Plain', 'Ugly')
    );

    showCombinations('', $traits, 0);

Having a real hard time of it. I'm a PHP programmer, and the way C handles strings is so much different. Could anyone offer some help?

It will be pretty different in C and I'm not going to write it all out for you. Why don't you post what you have so far so we can start from there?

If you cannot even start, then maybe you need to ask a simpler question, such as "How do I create an array of strings in C?" or "How can I duplicate a foreach() style loop in C?"

Sure:

Here is my code so far:

Code:

#include <stdio.h>
#include <string.h>

int printCombinations(char mystr[],int mystrIndex, char table[2][3], int tableLength, int currentIndex)
{
  int i;

  if (currentIndex >= tableLength)
    {
      printf("%s",mystr);
      printf("\n");
    }
  else
    {
      for (i = 0; i < tableLength; i++)
	{
	  mystr[mystrIndex++] = table[currentIndex][i];
	  currentIndex++;
	  printCombinations(mystr,mystrIndex,table,tableLength,currentIndex);
	}
    }
}

int main(void)
{
  char mytable[2][3];

  mytable[0][0] = 'a';
  mytable[0][1] = 'b';
  mytable[0][2] = 'c';
  mytable[1][0] = '1';
  mytable[1][1] = '2';
  mytable[1][2] = '3';
  
  char mystr[1000];
  int mystrIndex=0;

  printCombinations(mystr,mystrIndex,mytable,3,0);
  return 0;
}

In C, strings are simply arrays of chars, and can be passed around as pointers to the first char in that array. You could make your 2d array of type (char *) instead of (char) and initialize each one to the strings you had in your PHP. All the string functions in C expect a pointer like this, and will work properly when passed one of these pointers.

Other than that - do you have any specific questions or specific topics you're lost on? It seems like you know enough C to do most of that.

Part of what sean is I think getting at is that this:

Code:

char mytable[2][3];

  mytable[0][0] = 'a';
  mytable[0][1] = 'b';
  mytable[0][2] = 'c';
  mytable[1][0] = '1';
  mytable[1][1] = '2';
  mytable[1][2] = '3';

Is almost equivalent to this:

Code:

char mytable[2][4] = { "abc", "123" };

Except I added a char so that these can be strings, since expressed this way they will get null terminated. You don't actually use any string functions on them, tho, and if that is intentional:

Code:

char mytable[2][3] = { {'a','b','c'}, {'1','2','3'} };

is fine.

I'm a little confused about why you don't just use the string model from your PHP tho:

Code:

char *traits[] = {
	"Happy", "Sad", "Angry", "Hopeful",
	"Outgoing", "Introverted",
	"Tall", "Short", "Medium",
	"Handsome", "Plain", "Ugly"
};

These are literals and cannot be changed but will work for this.

Cross-posted

Originally Posted by rags_to_riches

Cross-posted

Thanks for that. I don't actually know PHP and suddenly realized I failed to take the array of arrays into account:

Code:

	char traits[][4][20] = {
		{"Happy", "Sad", "Angry", "Hopeful"},
		{"Outgoing", "Introverted"},
		{"Tall", "Short", "Medium"},
		{"Handsome", "Plain", "Ugly"}
	};

Now it's not literals anymore.