whats my error

Question

#include<stdio.h>

/*Printing odd numbers in the first and last column of a matrix*/

int add_matrix();//function declaration

int main()
{
int row, col;

printf("Enter the number of rows: ");
scanf("%d", &row);
printf("Enter the number of columns: ");
scanf("%d", &col);

int matrix[row][col];

for (int i=0; i<row; i++)
{
for (int j=0; j<col; j++)
{
printf("Matrix[%d][%d]: ", i, j);
scanf("%d", &matrix[i][j]);
}
}
add_matrix(matrix, row, col);
}

int add_matrix(int a[][],int row,int col)
{
int sum=0;
for (int i=0; i<row; i++)
{
if((a[i][1] % 2) != 0)
{
sum += a[i][1];
}
}
}

Answer 1

Function declaration not matching with definition... And must declare column size in array declaration..

void add_matrix(int a[][5],int i,int j);//function declaration

And you are not or output any result of calculations..

First column is indicated by a[ i ][0] and last column is indicated by a[ i ][col-1].

Col=1 indicates 2nd column as array indices are starts from 0.