Thread: pass array of different sizes as argument

Originally Posted by hacknItTogether

I will be monitoring this post for most the day if you have any further questions I can answer

Yes, is your name a Dr. Hook reference by any chance?

Also, do you know how to use a pointer-to-a-pointer?

Code:

char **matrix;

Originally Posted by hacknItTogether

yes I have used a pointer to a pointer

That is what you want to use as the third parameter to masterPrint. Getting that to work with a matrix declared like this:

Code:

char matrix[6][6];

is a bit of a hassle. After that, it is pretty straight-forward.

ouch, all my matrixes are char matrix[6][6]; that'd be a large code rewrite bad choice on my part but something to be learned. I was previously doing alot of C++ but switched to C for a different project it has taught me the niceness of C++. No sorry not a Dr.Hook reference, my boss always tells me don't hack it together no hacking, i'm infamous for grabbing portions of code throwing it into place just to get the job done

the arrays are defined at compile time and already exist. for example I have
DependenceMatrix[4][4]
ReachableMatrix[1][3]
MatrixPermutation[4][4]

I want

Code:

#include <stdio.h>
void matrixInit(char rowend,char columnend);
char Matrix[4][4];
void masterPrint(char rowend,char columnend, char matrixToBePassed);
int main()
{	
	matrixInit(4,4);
	masterPrint(4,4,Matrix);
}
void matrixInit(char rowend,char columnend)  
{
	char i=0;
	char j=0;
	for (i = 0; i < rowend; i++) 
	{
		for (j = 0; j < columnend; j++) 
		{
			matrix[i][j] = i + 1;                         
		}   
	}
}
void masterPrint(char rowend,char columnend, char matrixToBePassed)
{
	char i=0;
	char j=0;
	printf( "matrix print:\n");
		for (i=0; i < rowend; i++) 
		{
			printf( "row %d=", i);

			for (j=0; j < columnend; j++) 
			{
				printf("[%d]", matrixToBePassed[i][j]);
      
			} 
			printf("\n"); 
		}
}

Originally Posted by hacknItTogether

ouch, all my matrixes are char matrix[6][6]; that'd be a large code rewrite bad choice on my part but something to be learned. I was previously doing alot of C++ but switched to C for a different project it has taught me the niceness of C++.

Oh fluff -- don't listen to that tish. You do not have to do a major rewrite, you just need a couple of lines of code to assign a **ptp to your matrix, look:

Code:

#include <stdio.h>

void func(int x, int y, int **ptr) {
	int i, j;
	for (i=0;i<x;i++) {
		for (j=0;j<x;j++) printf("%d ",ptr[i][j]);
		printf("\n");
	}
}

int main(void) {
	int ray[3][3] = { {1,2,3},{4,5,6},{7,8,9} }, **ptr, i;
        /* whoops! I didn't initialize ptr, this code is bad */
	for (i=0; i<3; i++) ptr[i] = ray[i];
	func(3,3,ptr);
	return 0;
}

Those lines are in red. In C, we call this a hassle, but nothing to sweat n' fret over. In C++ maybe you throw up your hands and look for the HelpMe::Library, I dunno

Actually I'm gonna check out what tabstop is implying here...[later] nah that won't work.
[edit] Yes it will. Also the above has an overwrite in it...as noted in red

Originally Posted by tabstop

What I'm saying is that if matrixToBePassed is a char*, then *matrixToBePassed is a char, specifically the first character in the array, and we know how to print chars. Also matrixToBePassed+1 would then point to the next character, and matrixToBePassed+2 would then point to the character after that, and matrixToBePassed+3 would then point to the character after that....

Sure, and you could just use pointer arithmetic in masterPrint based on x & y. But this strategy will not work with 2D arrays declared matrix[x][x], unless you'd like to enlighten us with some code...