cant pass 2d array to function c code example

Example 1: passing 2d array as parameter to function in c

#include <stdio.h>

//passing 2D array as a parameter to a function
void fun(int *arr, int m, int n)
{
	int i, j;
	for (i = 0; i < m; i++){
	for (j = 0; j < n; j++)
		printf("%d ", *((arr+i*n) + j));
		printf("\n");
	}
}

int main(void)
{
	int arr[][4] = {{1, 2, 3,4}, {4, 5, 6,7}, {7, 8, 9,0}};
	int m = 3, n = 4; //m - no.of rows, n - no.of col

	fun(&arr, m, n);
	return 0;
}

Example 2: how to get input in 2d array in c

#include <stdio.h>

int main(){

    printf("Enter the number of columns");
    int i; 
    scanf("%d", &i);
    printf("Enter the number of rows");
    int y; 
    scanf("%d", &y);

    int r[i][y];
    int a;
    int b;

        for (a=0; a<i; a++){
            for (b=0; b<y; b++){
    scanf("%d",&r[a][b]);
        }
    }
}