Need help-decompression string

[Nastia Kozak]

hi,
Im trying to write a function that decompresses a string and returns the original string.
for example:
p3B2c4 will be pppBBcccc
this is what I have tried to do, the function returns nothing.
pls tell me where I'm wrong.

char *uncompress(char *coded_string)
{
	int size=0, i, j;
	char *original = (char *)malloc(size*sizeof(char));
	if (original == NULL)
	{
		printf("Dynamic allocation failed in uncompress\n");


		return NULL;
	}
	for (i = 0; coded_string[i] != '\0'; i++)
	{
		if (coded_string[i] >=1)
			
		size = size + coded_string[i] + 1;




	}
	for (j = 0; coded_string[j] != '\0'; j++)
	{
		if ((j % 2 )> 0)
		{
			original[j--] = coded_string[j];
		}
	}
	free(original);
	return original;
}

[Rusko]

When you step into the for(j=0...
Then j%2 has R=0 so 0!>0 so it doesnt step in to that if

is that meant to be? I would recommend some comments so i know what ur code is doing since u arnt self documenting

[whiteflags]

You need to analyse the string to come up with the right size before you call malloc(). It does no good to call malloc() with a size of zero and then expect it to grow.

I know you tried to do that, but it's easier to explain the other problems just starting over.

There's no place where you look for a digit character and respond based on that. It's a really important part to doing it right. You can figure out the size of your uncompressed string logically: "p3B2c4 " 3 + 2 + 4 = 9 characters long... "pppBBcccc" = 9 characters long.