Simplified Matrix Multiplication

#include <stdio.h>
#include <unistd.h>
#define DIM 4

double A[DIM][DIM];
double B[DIM][DIM];
double C[DIM][DIM]; #result of multiplication goes into this matrix

int main(void)
{
    int i, j, k;
    for ( i = 0 ; i < DIM ; i++ ){
        for ( j = 0 ; j < DIM ; j++ ){
            for ( k = 0 ; k < DIM ; k++ ){
                C[i][j] += A[i][k]*B[k][j];
            }
        }
    }
}