C Program to Add Two Matrices

The below program adds two square matrices of size 4*4, we can change N for different dimensions. 

C

// C program to implement
// the above approach
#include <stdio.h>
#define N 4

// This function adds A[][] and B[][],
// and stores the result in C[][]
void add(int A[][N], int B[][N],
         int C[][N])
{
    int i, j;
    for (i = 0; i < N; i++)
        for (j = 0; j < N; j++)
            C[i][j] = A[i][j] + B[i][j];
}

// Driver code
int main()
{
    int A[N][N] = {{1, 1, 1, 1},
                   {2, 2, 2, 2},
                   {3, 3, 3, 3},
                   {4, 4, 4, 4}};

    int B[N][N] = {{1, 1, 1, 1},
                   {2, 2, 2, 2},
                   {3, 3, 3, 3},
                   {4, 4, 4, 4}};

    // To store result
    int C[N][N];
    int i, j;
    add(A, B, C);

    printf("Result matrix is ");
    for (i = 0; i < N; i++)
    {
        for (j = 0; j < N; j++)
           printf("%d ", C[i][j]);
        printf("");
    }

    return 0;
}

Output:

Result matrix is
2 2 2 2
4 4 4 4
6 6 6 6
8 8 8 8

The program can be extended for rectangular matrices. The following post can be useful for extending this program. 
How to pass a 2D array as a parameter in C?
The time complexity of the above program is O(n²). 

The auxiliary space of the above problem is O(n²)