Passing a two dimensional array to a function in C - c

Question

#include <iostream>
#include <math.h>
#include <stdio.h>
#define column 3
#define row 3
#define share 3
int matrix_multiplication(int left_matrix[][column], int right_matrix[][column], int result_matrix[][column], int rows, int cols, int shared);
int A[][3] = {
{1, 2, 3},
{4, 5, 6},
{7, 8, 9}
},
B[][3] = {
{1, 2, 3},
{4, 5, 6},
{7, 8, 9}
}, C[3][3]; //initialize "hard coded" three matrices
int main() {
matrix_multiplication(A, B, C, row, column, share); //passes address of each matrix to function
return 0;
}
int matrix_multiplication(int left_matrix[][column], int right_matrix[][column], int result_matrix[][column], int rows, int cols, int shared) {
int i, j, k;
for (i = 0; i < 3; i++) {
for (j = 0; j < 3; j++) {//stays within first column and row through first iteration
for (k = 0; k < 3; k++)//ensures inner dimensions match with variable k i.e. ixk * kxj =ixj or A*B=C
result_matrix[i][j] += right_matrix[i][k] * left_matrix[k][j]; //C programming has ability to perform matrix multiplication
//Adds result of each operation to C matrix i.e. +=
printf("%d\t", result_matrix[i][j]); //matrix C is composed of rows(i) and columns(j)
}//new tab after each column iteration
printf("\n"); //new line for each row iteration
}
return 0;
}
This code is an good example of passing multidimensional arrays to a function using pointers and printing multidimensional arrays after mutliplication. There are multiple ways to indicate pointers to the compiler. I recommend seeing the "Correct way of passing a 2 dimensional array into a function." for example:
/*void display(int (*p)[numcols],int numRows,int numCols)//First method//
void dispaly(int *p,int numRows,int numCols) //Second Method//
void dispaly (int p[][numCols],int numRows,int numCols) //Third Method*/

Answer 1

Remove the column variable, and add this above the matrix_multiplication function declaration:
#define column 3
(You may also want to rename column to COLUMNS.)
In C++ you can also do this:
static const int column = 3;
or, in C++11:
constexpr int column = 3;
The idea behind all this is that all but the very first size of a multidimensional array must be known at compile time.
To fix the expected primary-expression before ']' token" error, change your inner assignment to something like this:
result_matrix[i][j] += right_matrix[i][k] * left_matrix[k][j];
Also you should initialize result_matrix with 0s first.
Also remove the * from int *result_matrix[][column].
Most modern compilers display warnings if you pass an int instead of an int*. Please enable all warnings in your compiler, recompile, fix them, and update your question stating that the example code compiles cleanly, without warnings.
To print an element of the matrix, you have to specify which element you want to print:
printf("%d\t", result_matrix[i][j]);
I can't believe that your compiler didn't display a warning when you omitted the [i][j]. Warnings are for your benefit: they indicate possible bugs in your code.