matrix in c

main() { int mat1[3][3] = {1,2,3,4,5,6,7,8,9}; int mat2[3][3] = {1,2,3,4,5,6,7,8,9}; int res[3][3]; int i,j,k; for (i=0; i<3; i++) for (j=0; j<3; j++) res[i][j] = 0; for (i=0; i<3; i++) for (j=0; j<3; j++) for (k=0; k<3; k++) *(*(res + i) + j) += (*(*(mat1 + i) + k)) * (*(*(mat2 + k) + j)); for (i=0; i<3; i++) { for (j=0; j<3; j++) printf ("%d\t", res[i][j]); printf ("\n"); } printf("\n"); }